W. S. Dallas

CHAPTER I.
INTRODUCTION—THE SQUIRREL, MARMOT, ANOMALURE, HAPLODONT, AND BEAVER FAMILIES.

Character of the Order—A well-defined Group—Teeth Evidence—Kinds and Number of Teeth—The Incisors: their Growth, Renewal, and Composition—The Molars—The Gnawing Process—Skeleton—Brain—Senses—Body—Insectivora and Rodentia—Food of Rodents—Classification—THE SIMPLE-TOOTHED RODENTS—Characteristics—THE SQUIRREL-LIKE RODENTS—SCIURIDÆ—Distinctive Features—THE COMMON SQUIRREL—Form—Distribution—Food—Bad Qualities—Habits—THE GREY SQUIRREL—THE FOX SQUIRREL—Flying Squirrels—Their Parachute Membrane—THE TAGUAN—Appearance—Habits—Other Species—THE POLATOUCHE—THE ASSAPAN—The Genus Xerus—THE GROUND SQUIRRELS—THE COMMON CHIPMUNK—THE MARMOTS—Distinguishing Features—THE SPERMOPHILES—THE GOPHER—THE SISEL, OR SUSLIK—THE BARKING SQUIRRELS—THE PRAIRIE DOG—Description—Species—Habits—Burrows—Fellow-inmates in their “Villages”—THE TRUE MARMOTS—THE BOBAC—THE ALPINE MARMOT—THE WOODCHUCK—THE HOARY MARMOT, OR WHISTLER—ANOMALURIDÆ—Tail Peculiarity—Distinctive Features—HAPLODONTIDÆ—Description—THE SEWELLEL—CASTORIDÆ—THE BEAVER—Skeletal Peculiarities—General Form—Appearance—Distribution—The Beavers of the Old and New World—Habits—Wonderful Sagacity—The Building Instinct—Their Method of Working—The various Stages—Their Lodges—Their Dams—Activity by Night—Flesh—Hunted—The Castoreum.

WHILE the last few chapters have been devoted to orders which contain the largest and most powerful of terrestrial mammalia, we have now to treat of a group, all the members of which are of comparatively small size. “Mice, rats, and such small deer,” to use Shakspere’s phrase, make up a great proportion of the order Rodentia. The biggest of them is only about the size of a small Pig; and perhaps the common House Rat, or, at any rate, the common Squirrel, may be taken as showing the average dimensions of a Rodent. But, although from this point of view they may be looked upon as “a feeble folk,” their numerous species render them a most important section of the mammalian fauna of nearly all countries, and this importance is greatly increased, practically, by the immense number of individuals by which each species is usually represented.

The Rodentia, or gnawing mammals—GLIRES, as LinnÆus and some modern zoologists call them—notwithstanding the great number of the species and the immense variety of forms which they display, constitute, perhaps, the most definitely circumscribed order of the Mammalia. In most other groups of the same value, we find that some types exhibit divergent characters, which render it difficult to frame a general description of the order which shall include them; or else some species present a marked tendency towards some other order; but in the case of the Rodents, we never have any difficulty, a cursory inspection of the dentition is always sufficient to decide whether a quadruped belongs to the Rodentia or not; and in spite of an almost infinite variety of form, the structure of the rest of the organism is most clearly in accordance with the evidence derived from the teeth.

SKULL OF THE TAGUAN, A FLYING SQUIRREL.

The teeth are only of two kinds—incisors and grinders (see the above figure of the skull of the Taguan)—and the number of efficient teeth of the former kind is never more than two in each jaw. Almost throughout the order, indeed, there are actually, even from the first, only two incisors present; but in the Hares and Rabbits, and some allied forms, there are in the upper jaw, in addition to the working teeth, a pair of rudimentary incisors,[48] placed immediately behind the large ones, but quite incapable of taking any part in the business of gnawing, for which the latter are so admirably fitted. Their presence is, however, of interest, as indicating the direction in which an alliance with other forms of Mammalia more abundantly supplied with teeth is to be sought.

DENTITION OF THE HARE.

The great incisors, which are characteristic of the Rodents, exhibit the following peculiarities:—They possess no roots, but spring from a permanent pulp, so that they continue growing during the whole life of the animal; and their form, and that of the cavity which constitutes their socket, is always that of a segment of a circle,[49] in consequence of which, they always protrude from the front of the jaws in the same direction, and meet at the same angle. By this means, as the teeth are worn away at their summits by use in gnawing, a fresh supply of tooth is continually being pushed forward to take the place of the portion thus removed, and, in fact, so intimately are the two functions of use and growth correlated in the teeth of these animals, that if by chance one of the incisors should get broken, or the natural opposition of these teeth should be disturbed in consequence of injury to the jaw, the teeth, thus deprived of their natural check, continue growing, and, following the curve of their sockets, gradually form circular tusks, which must always be greatly in the way of the animal when feeding, and sometimes, by actually penetrating again into the mouth, cause its death by absolute starvation. The teeth themselves are composed of dentine, coated along the front surface with a layer of hard enamel, which substance is wanting on the other surfaces of the teeth, except in the Hares, Rabbits, and other forms with additional rudimentary incisors in the upper jaw, in which, as further evidence of their relationship to the other Mammalia, the whole surface of the incisors is encased in enamel, although this coat is excessively thin except on the front or outer face. The purpose of this structure of the incisors is easily understood. In the action of gnawing, the dentine, which forms the greater part of the tooth, is more easily abraded than the harder enamel, which is thus left as a sharp front edge, to which the mass of dentine behind it, being worn away into a bevelled surface, gives the necessary firmness and support, the whole forming a chisel-like instrument, constructed precisely on the principle of those tools in which a thin plate of hard steel forms the cutting edge, and is stiffened by a thicker bevelled plate of softer iron.

The canine teeth are entirely deficient, and behind the incisors we find on each side a toothless gap of considerable extent (see figures p. 82), beyond which come the grinding teeth. In these it is difficult to recognise any distinction of molars and pre-molars; the whole series presents nearly the same structural characters, and for all practical purposes we may speak of them as molars, although some zoologists prefer to regard the three hindmost teeth on each side as true molars, and any others that may be present as premolars. In one genus (Hydromys) the number of grinding teeth is reduced to two on each side in each jaw; in a great proportion of the species the number is three; others have four or five grinders on each side, either in one or both jaws (usually one more in the upper series); and the largest number is possessed by the Hares and Rabbits, in which the upper jaw has six and the lower five grinders.[50] The grinders are sometimes furnished with true roots, but are more commonly open below, and provided, like the incisors, with a permanent pulp. They are sometimes tubercular, at least in youth, but generally show a flat, worn surface with transverse bands, or re-entering folds, and sometimes cylinders of enamel, which display a great variety of patterns. Sometimes the enamel is confined to the surface of the tooth; in other cases each tooth is, as it were, made up of two or more variously-shaped tubular portions of enamel, filled up with dentine. Curiously enough, this structure of the grinders, especially the arrangement of the transverse ridges and plates of enamel in these little animals, reminds us strongly of the characters of the molars of the gigantic Proboscidea, in which, moreover, the incisors also are represented by the permanently-growing tusks.

The articulation of the lower jaw with the skull is peculiar, and in special relation to the armature of teeth which we have described. Instead of articulating freely, as in man and many herbivorous mammals, by which provision is made for a sort of rotatory action of the molars, or by a regular transverse hinge-joint, as in the Carnivora, the articulating surfaces are elongated in a direction parallel to the middle line of the skull, an arrangement which, like that occurring in Carnivora, has the effect of preventing much lateral movement of the jaw; but, at the same time, the pits with which the jaw articulates are open in front, so that the jaw is allowed a certain amount of play, backwards and forwards. This motion greatly increases the gnawing power of the large incisor teeth.

SKELETON OF THE RABBIT.

The head in the Rodents is generally of small or moderate size in proportion to the body, and the skull is usually rather elongated, and flattened on the upper surface. The tympanic bullÆ are generally of considerable size; the zygomatic arch is in nearly all cases well developed; but the orbits of the eyes are never closed behind, and only in certain families is there even a small process of the zygomatic arch behind the orbits, as an indication of possible closure. Of the vertebral column we need only say that the lumbar vertebrÆ are remarkable for possessing large transverse processes directed forwards, and that the tail varies greatly in length, being sometimes longer than the body, sometimes reduced to very small proportions, whilst between these two extremes almost every grade of development may be met with.

The sternum, or breast-bone, is usually long and narrow. Collar-bones are nearly always present, but in a few forms they become rudimentary, or even disappear altogether. The pelvis is long and narrow. The limbs exhibit a very great variety in their development; in many, the two pairs are nearly equal in length, but in the majority the hind limbs are distinctly longer and more powerful than their fellows, and in some groups they attain a most disproportionate length, and serve almost exclusively as the organs of locomotion. On the other hand, in the great majority of the order, the fore limbs serve in a certain degree as hands, and are used for holding the food to the mouth; and in these the radius and ulna, which are always distinct bones, retain the power of rotation. The corresponding bones in the hind limbs (tibia and fibula) are, on the contrary, firmly anchylosed together in two great groups of the order. The feet have usually five toes, but sometimes this number is reduced to four, or even to three, in the hind feet. These toes are armed with claws, which, however, in one family, acquire more or less of the appearance of hoofs.

In point of intelligence the Rodentia do not stand high. The brain is comparatively small, and the cerebral hemispheres show no traces of those convolutions of the surface which are characteristic of most Mammals (see figures). The Capybara alone is known to have a few convolutions. The cerebellum is entirely uncovered by the hemispheres. The organs of the senses are generally well developed, and the eyes and external ears, especially, are often of large size. In the Mole Rats and some other burrowing forms, however, the external ears are entirely wanting, and the eyes are very much reduced in size, and in some instances even concealed beneath the skin. The intestinal canal is long, and in all but one family furnished with a distinct cÆcum.

BRAIN OF BEAVER (from above).

BRAIN OF BEAVER. (Profile.)

The body in the Rodents is generally plump and short, and the head is borne upon a short neck. The limbs also are usually short, so that the belly is close to the ground; but in some cases all four legs are of moderate length, or, as already stated, the hind legs are enormously developed, forming powerful leaping organs. In general structure, as to a certain extent in habits, there is, in fact, a most striking parallelism between the Rodentia and the Insectivora (see Vol. I., p. 343); in both we find arboreal and terrestrial forms, and among the latter some specially organised for burrowing in the earth, and others equally adapted for springing lightly over its surface; a few, also, in both orders, are aquatic. But here the parallel ceases. The dentition in the two groups is widely divergent, and, as might be anticipated from this circumstance, the food is very different; for, although some Rodents, such as the common Mouse and Rat, are omnivorous, there is no doubt that, as a whole, the Rodents must be regarded as vegetarians. Grass and the leaves of plants and trees furnish some of them with nourishment; whilst others feed upon fruits, seeds, and nuts, in the consumption of which last the powerful incisor teeth come into play. Many species lay up stores of food for the winter season, of which they pass more or less in a state of torpidity; and some of these are provided with cheek-pouches, often of considerable size, in which to convey their harvest into their store-houses.

As might be expected from the great number of species belonging to this order, and their general uniformity of structure, their classification is a matter of some difficulty, and very different views as to their relationships have prevailed at different times. Nowadays, however, zoologists have arrived at something like uniformity of opinion in this matter, and except in some minor points they may be said to be pretty nearly agreed. In the following sketch of the natural history of the Rodents we shall follow the classification proposed by the late Mr. E. R. Alston in the Proceedings of the Zoological Society. Mr. Alston accepted the division of the order into two primary groups (sub-orders), proposed fifty years ago by Professor Gervais, and characterised by the number of incisor teeth. The first of these sub-orders, which includes by far the majority of the Rodents, is formed by those species which never at any period of their lives possess more than two incisors in the upper jaw, and have the enamel on these strictly confined to the front surface of the teeth. These are denominated SIMPLICIDENTATA, or SIMPLE-TOOTHED RODENTS. In the second group, which includes only the Hares, Rabbits, and Calling Hares, we have those species which in the adult state possess four incisors in the upper jaw, namely, two large and efficient teeth, and behind these two small, almost rudimentary incisors (see figure of the dentition of the Hare on p. 82). These are called DOUBLE-TOOTHED RODENTS, or DUPLICIDENTATA.

Besides the characters derived from the number of incisor teeth above mentioned, several other peculiarities of structure seem to show the existence of a decided difference between the Simple-toothed and Double-toothed Rodents; but most of these are of a rather abstruse nature, and need not be noticed here, the most important additional distinctive characters of the former being that the bony palate is well developed, and that the fibula does not articulate with the calcaneum, or heel-bone; whereas in the Double-toothed Rodents the palate is reduced to a mere bridge between the portions of the upper jaw in which the teeth are inserted, and the fibula does articulate with the heel-bone.

The Simplicidentata include a great number of families, and various attempts have been made to group these under larger heads; but it must be confessed that, owing to the way in which the families approach one another, it is difficult to bring them together in sections capable of being very strictly defined. Certain broad principles of relationship are, however, generally recognised, and Mr. Alston represented these by placing the Simple-toothed families under three great sections, the first indicated by Mr. Waterhouse—the Squirrel-like, Mouse-like, and Porcupine-like Rodents.

The Squirrel-like Rodents have four molars on each side in the lower jaw, and either four or five in the upper. When the latter number is present, the foremost tooth is smaller than the rest. The fibula remains as a distinct bone through life, and is usually quite free, although sometimes attached to the tibia at the extremity. The upper lip is usually cleft, the muffle is small and naked, and the nostrils are comma-shaped, with the rounded part above. The zygomatic arch is formed chiefly by the process of the malar bone, which is not supported below by a continuation of the zygomatic process of the maxillary. The collar-bones are perfect. The tail is usually cylindrical and hairy.

The Mouse-like Rodents agree with the preceding in the characters of the upper lip, muffle, and nostrils, but they have the tibia and fibula completely united for at least the last third of their length. The zygomatic arch is slender, and the malar process rarely extends so far forward as in the preceding group and is generally supported below by a continuation of the maxillary process. The collar-bones are perfect, except in one very small family; and the tail is cylindrical, and although sometimes hairy, more commonly covered with scales arranged in rings. The number of molar teeth in this section varies from three to six[51] on each side in each jaw, but three is the most usual number.

TEETH OF THE TAGUAN.

The Porcupine-like Rodents, with one exception, have four molars on each side in both jaws; the fibula distinct throughout life; the upper lip rarely cleft; the muffle clad with a velvety coat of fine hairs; and the nostrils either S-shaped or straight. The zygomatic arch is stout, and the malar process does not advance far forward, nor is it supported below by the maxillary process.

SECTION I.—(SCIUROMORPHA.) SQUIRREL-LIKE RODENTS.

FAMILY I.—SCIURIDÆ.

This first family, which includes the true Squirrels and the Marmots, is distinguished from the rest of the section by the possession of five rooted molars on each side of the upper jaw (see figure of the teeth on p. 85), the first being very small and sometimes deciduous, and four molars on each side of the lower jaw, and by the presence on the skull and zygomatic arch of small processes, indicating the posterior boundary of the orbits (see figure of the skull on p. 82). The molars are tubercular, at least at first; but the summits of the tubercles are generally more or less worn down as the animal increases in age.

COMMON SQUIRREL.

The true Squirrels, which may be regarded as the types of this family, are distinguished by their slender and graceful forms, and their long and generally bushy tails, the latter character having originated their classical name of Sciurus, as a compound of two Greek words, indicating their habit of carrying their tails thrown up, so as to shade the back. Our COMMON SQUIRREL (Sciurus vulgaris) may serve as a good example of this division of the family. It is too well known as a pet to need any detailed description; its elegant form and graceful movements, the rich brownish-red colour of its upper surface, contrasting with the white of the belly, and the beautifully-pencilled or tufted ears, which, combined with its bright black eye, give it such a lively appearance, must be familiar to every one. When full-grown, the Squirrel measures from eight to ten inches in length of body, and has a tail seven or eight inches long. British specimens are generally smaller than those from the Continent of Europe. It varies considerably in colour with the seasons, especially in northern regions; but even in Central Europe and in Britain the fur of the sides and back becomes mixed with a certain quantity of greyish-white hairs in the winter, whilst in Lapland and Siberia the whole upper surface acquires a grey tint at that season. In the summer also the ear-tufts diminish, or altogether disappear. In the Alps and Pyrenees, there is a variety having the back of a dark brown colour, speckled with yellowish-white. This has been described as a distinct species, under the name of Sciurus alpinus.

The Common Squirrel is a widely-distributed species. It is abundant all over Europe, except, according to Pallas, in the Crimea, and extends beyond the Ural Mountains through the whole length of Southern Siberia to the Altai and the Amoor region. It occurs in the Caucasus, and probably in Persia. Everywhere it haunts the woods and forests, living chiefly upon the trees, among the branches of which it displays the most astonishing agility. On the ground—to which, however, it does not often descend—it is equally quick in its movements. If alarmed under these circumstances, it dashes off to the nearest tree with lightning-like rapidity, and by the aid of its sharp claws rushes up the trunk till it has reached what it considers a safe elevation, when the little sharp face and bright eyes may be seen peeping at the intruder, apparently in triumph over his supposed disappointment.

The food of the Squirrel consists chiefly of nuts, beech-mast, acorns, and the young bark, shoots, and buds of trees. In eating the former articles, they are held in the fore-paws, which thus supply the place of hands, and the strong incisors soon make a way through the outer shells into the contained kernels, which alone are eaten; for in all cases in which the kernel is coated with a coarse brown skin (as in the common hazel-nuts), the Squirrel carefully removes every particle of this from the portions on which he feeds. The bark, buds, and young shoots of trees seem generally to be attacked by the Squirrel when he finds a deficiency of other and more congenial nourishment; but this is so regularly the case in the spring of the year, that these animals actually cause a great amount of damage to the trees in forest regions. Hence, not unnaturally, the Squirrel is regarded in forest countries as a most mischievous little animal, whose depredations are not to be condoned on account of its elegant appearance and lively habits. As another unamiable quality, may be mentioned its habit of plundering birds’ nests and eating the eggs, which appears to be established upon unquestionable evidence. In some northern regions the inhabitants turn their Squirrels to a more profitable use than putting them, as we so often do, into a sort of treadmill. In Lapland and some parts of Siberia, especially on the banks of the Lena, these animals are killed in great numbers for the sake of their grey winter-coats, which, however, are not equal in beauty to those of the north American Grey Squirrel.

The Squirrel passes the greater part of the winter in a torpid state, lying coiled up in some hole of a tree, where its long bushy tail is of service in keeping it warm and comfortable. On fine and warm days, however, it rouses itself from its slumbers; and, as if foreseeing the occurrence of such days, it lays up in the autumn stores of nuts, acorns, and beech-mast, upon which it can feed when it wakes during the winter. This winter provision is not laid up all in one place, but stored away in several different holes in trees surrounding the place of its own retreat.

Squirrels appear to be strictly monogamous, pairing for life, and constantly inhabiting the same dwelling. The young, three or four in number, are produced in June, and for their reception the parents prepare a very beautifully constructed nest, formed of interlaced moss, leaves, and vegetable fibres, which is placed either in the hole of a tree, or in the fork between two branches. The young Squirrels are very carefully attended by both parents, and the family remains united until the following spring, when the young go out to find partners, and settle themselves in the world.

The Common Squirrel may serve as an example of the whole genus Sciurus, which includes the ordinary Tree Squirrels, the species of which are very numerous, probably more than one hundred, and distributed over nearly all parts of the world. The species are most numerous in the warm Oriental regions, in India, and the countries and islands lying to the east of it, from which nearly fifty species have been recorded. The northern parts of the Old World only possess half a dozen species, but North America has about eighteen, many of which are considerably larger than the European Squirrel. The most striking of the North American species are the GREY SQUIRREL (Sciurus carolinensis) and the FOX SQUIRREL (Sciurus niger), both of which are abundant in the Atlantic States, and vary considerably in colour, presenting both grey and black individuals.

BLACK FOX SQUIRREL.

Besides the ordinary Squirrels, a considerable number of other species are arboreal in their habits, and, indeed, even more strictly so than the true Squirrels. These are the Flying Squirrels, as they are called, which may be at once distinguished from the others by the presence of a large fold of skin, extending along the sides of the body, and including the limbs as far as the wrists and heels (see figure on next page). In the case of the Common Squirrels, it is observed that in performing leaps of any considerable extent the limbs are stretched out, and the long, bushy tail extended, so as to give the animal as large a surface as possible; but in the Flying Squirrels, as in the Flying Lemur (Vol. I., p. 344), when the limbs are extended laterally the folds of skin (patagia) become tightly stretched, and form a regular parachute, which seems to give the animal essential support in its most extensive leaps. The extent of this membrane is increased by means of a sort of bony spur, which articulates with the wrist.

The TAGUAN (Pteromys petaurista) is a large species, indeed, the largest of the whole family SciuridÆ. It measures about two feet long, and has a bushy tail of nearly equal length. Its ears are pointed, but not tufted, and its eyes are large and prominent. Its colour above is greyish-black, produced by a mixture of entirely black hairs with others having the tips greyish-white; beneath it is greyish-white. About the head and on the limbs the fur is tinged with brown or chestnut brown, and the lateral folds are sometimes of the latter colour, sometimes blackish-brown above and grey beneath. The tail is rounded in its form.

This species inhabits the peninsula of India and Ceylon, Malacca and Siam, where it is found only in the forests, living in trees, either singly or in pairs. Its activity is chiefly nocturnal, in which respect it differs from the ordinary Squirrels. During the day it sleeps in the holes of trees, but at night it comes forth, climbing and leaping with the greatest rapidity about the trees on which it lives. While thus engaged the lateral membranes are loosely folded at the sides of the body; but from time to time the Squirrel wishes to pass from one tree to another at some distance, and then it ascends to a considerable elevation and springs off, at the same time extending all four limbs as much as possible, when the tightly-stretched folds of skin lend the body a support, which enables it to glide through the air to some distance, although it seems always to alight at a lower level than that from which it started. During these aerial excursions the long bushy tail serves as a sort of rudder, and enables the animal even to change its course during flight. Of the habits of the Taguan very little is known. It appears to feed upon fruits, and is exceedingly shy and fearful. Of a nearly-allied species which he observed in China, Mr. Swinhoe says that the nest, which was placed high up in a large tree, measured about three feet in diameter, and was composed of interlaced twigs, and lined with dry grass. It contained only a single young Squirrel; but this might be exceptional.

TAGUAN.

Some nine or ten additional species of the genus Pteromys, which includes the Flying Squirrels with cylindrical tails, are found in the forest regions of India and of the countries to the east of that peninsula, including China, Formosa, and Japan. The same region also harbours three or four species of another kind of Flying Squirrel, in which the long hairs of the tail are arranged in two rows, and the tail is flat instead of cylindrical. These animals, to which the name of Sciuropterus has been given, are, however, more numerous in the north, where their distribution extends from Lapland and Finland, through Siberia, to Northern China and Japan. Squirrels of this genus also occur over the whole continent of North America and as far south as Guatemala. The best known of the Old World species is the POLATOUCHE (Sciuropterus volans), which inhabits the north-eastern parts of Europe and nearly the whole of Siberia. It is an elegant little creature, about six inches in length, and with a broad, flat tail, rather shorter than the body: as, indeed, is the case in all the Sciuropteri. Its silky coat is in summer of a tawny brown on the upper surface, darker on the flying membrane and the outsides of the limbs, beneath pure white; whilst the tail is greyish above and light rusty red beneath. In winter the fur becomes longer and thicker, and appears of a silver grey colour on the upper surface. The Polatouche lives in the birch woods, or in places where pines, firs, and birches grow intermingled; but the presence of the birch seems to be a necessity of its existence. It is met with singly or in pairs, but always on the trees, sleeping during the day in its nest or in the hole of a tree, and coming forth at dusk to climb and leap about the branches with great agility. In going from tree to tree by the aid of its lateral membranes, it is said to cover distances of twenty or thirty yards with ease, always, however, taking its leap from the highest branches of the tree it starts from, and alighting at a considerably lower level. Its food consists of nuts, seeds, berries, the buds, young shoots, and catkins of the birch, and the young shoots of pines and firs. The nest is made in the hole of a tree, carefully lined with soft moss and herbage. Like the Common Squirrel, the Polatouche sleeps through the cold weather, but wakes up from time to time and goes out in search of food.

POLATOUCHE.

This group of Flying Squirrels is also represented on the North American continent. The number of species seems rather uncertain, some authors making it two, others four; while Mr. J. A. Allen regards all the North American Flying Squirrels as belonging to a single species, which varies greatly in size in different localities. This species is the ASSAPAN (Sciuropterus volucella), one of the smallest of its family, the length of its head and body being only from four and three-quarters to seven and a half inches; the smaller specimens (var. volucella) being found in the more southern States, and even as far south as Guatemala; and the larger ones (var. hudsonius) in more northern localities. In its habits this elegant little Squirrel resembles the Polatouche, but appears to be more sociable. It thrives well in confinement.

Besides these Tree Squirrels, a few species of the Sciurine sub-family live upon the ground. In Abyssinia and in other parts of Africa some curious animals, forming the genus Xerus, are found, distinguished by their very small ears, longish limbs, and the singular texture of their hair, which scantily clothes the skin and generally takes the form of flattened spines. They have a slender body, a pointed head, and a longish tail. These animals live in elevated forest regions, and even upon comparatively barren steppes, where they burrow in the ground under rocks, or among the roots of trees and bushes. They are diurnal, and feed chiefly upon buds and herbage, but also devour small birds, eggs, and insects. The best known species (Xerus rutilans) is about twenty inches long, of which the tail makes about nine inches. Its colour is reddish-yellow above, becoming paler on the sides, and whitish below.

COMMON CHIPMUNK.

The true GROUND SQUIRRELS (Tamias) are distinguished from the rest of the Squirrels (SciurinÆ), and approach the Marmots, which form a second sub-family of SciuridÆ. Like some of the latter, they possess large cheek-pouches opening into the mouth. The ears in this genus are short; the fourth toe of the fore feet is longer than the rest, as in all the SciurinÆ; the limbs are short, and nearly equal in length; and the tail is shorter than in the true Squirrels. In general form and appearance, however, the Ground Squirrels greatly resemble the latter, except that they are rather stouter in the body. Four species of this group inhabit the continent of North America, where they are known as Chipmunks; and one of these, according to Mr. J. A. Allen, is identical with the only known Old World species (Tamias asiaticus), which is found in North-eastern Europe and across Northern Asia, as far as the mouth of the Amoor, North China, and Japan. This species, which goes by different names in the different localities which it inhabits, and the COMMON CHIPMUNK (Tamias striatus) of the United States, agree very closely in all respects, and are exceedingly pretty little animals, with light-coloured fur adorned with darker stripes, varied in the case of the Chipmunk with streaks of white. They are from eight to ten inches long, including the tail. These animals live in burrows in the ground, and feed upon nuts, acorns, grain, and other seeds of various kinds, of which they lay up great stores in the autumn, carrying home their provisions in their cheek-pouches, which they stuff as full as they can hold. In this way they do no small damage to cultivated grounds near their haunts, plundering the corn and maize fields very freely; over eight pounds of corn in the ear are often found in the granaries of the Siberian form. The burrow is made deep enough to protect the animals from frost in winter, and the sleeping chamber contains a large nest of leaves and grass, in which several individuals, probably the parents with their grown-up family, sleep through the cold weather; but it must be remarked that their torpidity is very imperfect, and that they have frequent recourse to the supplies of food which they have stored up during the summer and autumn in separate chambers at the ends of lateral passages. These stores are so large that they generally greatly exceed the wants of the provident little animals, and in the spring the residue is greedily devoured by Wild Pigs and Bears. Even the poorer human inhabitants of the countries frequented by the Ground Squirrels do not disdain to eke out their scanty means of subsistence by plundering the hoards of these animals. Many of them perish in severe winters, great numbers are destroyed by man, by the smaller Carnivora, and by birds of prey, but, nevertheless, they manage to hold their own, in consequence of the great fertility of the females, which produce several young twice in the year, namely, in May and August. At pairing time the males fight violently.

MOLAR TEETH OF THE MARMOT.

From the Ground Squirrels we pass, by a perfectly natural transition, to the MARMOTS (ArctomyinÆ), the second sub-family of SciuridÆ. These animals differ from the preceding forms by their broader incisors, shorter tail, and stouter form of body, and by having the third finger longer than the rest. The first upper molar, also, is larger and more persistent than in the Squirrels, and the other molars differ in structure (see figure). The Marmots are all terrestrial animals, living and storing provisions in burrows, which they dig in the ground, and they are strictly confined to the northern parts of the two hemispheres.

STRIPED SPERMOPHILE, OR GOPHER.

BURROWS OF THE PRAIRIE DOG.

The nearest approach to the Squirrels is made by the SPERMOPHILES (Spermophilus), several species of which occur in North America from Mexico to the Arctic regions, but never to the east of the great central prairie region; whilst in the Old World their domain extends from Silesia, through Russia, and across Asia, to the Amoor and Kamstchatka. The Spermophiles are Squirrel-like in form and have rather short tails, but in the American species this organ is generally longer than in those of the Eastern continent. On the thumb the claw is either very small or altogether wanting; the two series of molars are nearly parallel, and the mouth is furnished with large cheek-pouches. The ears are very small. These animals live in society, and prefer a dry, sandy, or loamy soil, in which they can easily make their burrows, which terminate in a chamber lined with grass and herbage, and have, besides, side-chambers, in which provisions can be stored for winter use. Like the other species of the family, the Spermophiles pass the winter in a state of partial torpidity. In the summer they are exceedingly lively and playful. Their food consists of roots, berries, and seeds of various kinds, and their winter stores of these articles are carried into the burrows in their large cheek-pouches. The females are very prolific, producing from four to eight young at a birth, and in some cases even as many as ten have been found. The commonest and most widely distributed of the North American species is the STRIPED SPERMOPHILE, or GOPHER (Spermophilus tredecimlineatus), a pretty little creature of from six to eight inches long, usually of a chestnut brown colour with seven yellowish-white lines running along the back and between these six rows of small squarish spots of the same colour. This species extends its range from the Red River in Canada southwards as far as Texas, and is common on the prairies east of the Mississippi. This and some other species of the genus are said to be very carnivorous in their habits, preying upon small birds and mammals; and the Gopher was even described as feeding upon the flesh of Bisons, which it found lying dead on the prairies. The other American species are more local in their distribution; four of them occur in Mexico, and one of these is only known from that country. Of the Old World species the best known is the SISEL, or SUSLIK (Spermophilus citillus), which is abundant in Central and Eastern Europe and in Siberia. Several other species are known from Asia Minor, Siberia, and Central Asia.

The BARKING SQUIRRELS, or PRAIRIE DOGS, of which two species (Cynomys ludovicianus, see figure on p. 81, and C. columbianus) are found in the United States of America, are of a stouter form than the Spermophiles, and have the ears and tail short. The claws are well developed on all the toes of the fore feet, the cheek-pouches are shallow, and the two rows of grinding teeth converge towards the back of the mouth. These animals are peculiar to North America, where the former inhabits the prairies east of the Rocky Mountains, and the latter is found on the plains of the Columbia river, and in other parts of the western territories as far south as New Mexico. The best known of the two species is the Cynomys ludovicianus, to which the name of the PRAIRIE DOG was first applied: this name being given to it from a fancied resemblance of its voice to the barking of a small Dog. It measures about a foot in length, and its tail is about four inches long. Its colour on the upper surface is reddish-brown, variegated with grey, and with a few scattered black hairs; the tail is flattened, and brownish-black towards the end, and the lower surface is brownish or yellowish-white. These animals live together in great societies, especially upon those portions of the prairies where the so-called buffalo-grass (Sesleria dactyloides) grows most luxuriantly, this grass and succulent roots constituting their chief food. They live in burrows, which they dig in the ground at a distance of twelve or fifteen feet apart; a hard-beaten path runs from burrow to burrow, and would seem to give evidence of the sociable disposition of the animals; and at the mouth of every burrow there is a little hillock, formed by the earth thrown out of it, which serves the occupant as a watch-tower. These burrows are usually so numerous upon favourable pieces of ground that the space occupied by them is quite populous, and presents a scene of considerable animation when the inhabitants are out in the pursuit of their business or their pleasure, and hence they are in common parlance spoken of as “towns” or “villages.” Their curious appearance is heightened by the almost constant presence in them of numerous small Owls, of the species known as the Burrowing Owl (Athene cunicularia), a widely-spread species, which in some places digs its own subterranean habitation, but on these prairies saves itself the trouble by taking possession of the deserted abodes of the Prairie Dogs. These birds are diurnal in their habits, and are to be seen mixed up with the Prairie Dogs in their settlements. Another inhabitant of the burrows is the Rattlesnake; and some of the earlier observers thought that the Prairie Dogs, Owls, Rattlesnakes, and some other animals, such as Horned Frogs and an occasional Tortoise, occupied the same burrow, and lived there on the most amicable footing. Unfortunately, this paradisaic picture is an imaginary one. It is true that the Rattlesnake does take up his abode in the Prairie Dog’s burrows, but he either selects a deserted one, or dispossesses, and perhaps devours, the rightful owner; and his object in his residence among the lively little Marmots is anything rather than peaceful, as they constitute his favourite food. The little Burrowing Owl has also been said by some writers to feed on the young Prairie Dogs; but this is not proved, and the food of the Owls is known to consist chiefly of Grasshoppers and Crayfish. According to the latitude in which they live, the Prairie Dogs seem to be more or less subject to torpidity during the winter.

The true MARMOTS (Arctomys) are nearly related to the Prairie Dogs. They are stout in the body, have a short tail, and a rudimentary thumb with a flat nail; and are either entirely destitute of cheek-pouches or have mere indications of those organs. The rows of molar teeth are placed nearly parallel to each other in each jaw. The skull is broad and flat above, with a depression between the orbits; and the post-orbital processes are larger than in any other SciuridÆ. The Marmots are confined to the Northern hemisphere, but over it they are widely distributed in both continents. Of the Old World species, the best known are the BOBAC (Arctomys Bobac) and the ALPINE MARMOT (A. Marmota), of which the former extends from the south of Poland and Galicia over the whole of Southern Russia and Siberia to the Amoor region and Kamstchatka, whilst it is found in elevated situations as far southward as Cashmere, Tibet, and the Himalayas; and the latter inhabits only the higher regions of the Alps, Pyrenees, and Carpathians. In North America the common species is the WOODCHUCK (Arctomys Monax), the distribution of which is from the Carolinas northward to Hudson’s Bay, and westward from the Atlantic coast to Missouri, Iowa, and Minnesota; the Rocky Mountain region is inhabited by a distinct species (A. flaviventer); and a third very large species, the HOARY MARMOT, or WHISTLER (A. pruinosus), which measures from twenty-three to twenty-five inches in length of body, appears to be most abundant in the north-western parts of the continent, and is said to range northward as far as the Arctic Circle. The Marmots live usually in large societies in extensive burrows, which they form underground; and in some localities, as on the great plains of Russia and Siberia, their dwelling-places are described as producing a remarkable effect, owing to the multitude of little hillocks formed by the earth thrown out of their burrows. During the summer they are in a state of constant activity, playing and running about in search of food in the neighbourhood of their dwellings. The winter they pass in a state of torpidity, in a comfortable chamber lined with soft herbage, and protected from the outside cold by the closure of the main passage leading into their abode. For a time after their retirement for the winter they continue active in their domicile, and feed upon the stores of food which they have laid up during the summer; and as a preparation for their winter sleep, they become exceedingly fat during the autumn. The Marmots are the largest members of their family, and, indeed, some of them may be reckoned among the larger Rodents. The Alpine Marmot measures more than twenty inches in length, and the Bobac about fifteen inches, exclusive of the tail.

ALPINE MARMOT.

FAMILY II.—ANOMALURIDÆ.

Some curious African animals, closely resembling the Flying Squirrels, and at first regarded as belonging to that group, were formed by Mr. Waterhouse into a distinct genus, which he called Anomalurus, in allusion to the peculiar characters presented by their tail. This organ, which is long and well clothed with hair, although not so bushy as in the true Squirrels, has on the lower surface of its basal portion a double series of horny scales, which project from the skin, and probably serve to assist the animal in climbing upon the branches of trees.

Besides this peculiarity, these animals exhibit certain other characters which have induced modern zoologists to separate them from the Squirrels as a distinct family. Thus, the post-orbital processes are wanting, or nearly so; the infra-orbital openings are large; the molar teeth are four in number on each side, above and below, nearly equal in size, and not tubercular, but with a flat surface, crossed by transverse loops of enamel; and the palate is contracted in front and deeply notched behind. In the skeleton we find sixteen pairs of ribs, whereas in the Squirrels there are only twelve or thirteen pairs; and the internal anatomy, first described by Mr. Alston, is very peculiar. The flying membrane is quite as largely developed as in the Flying Squirrels, and is in the same manner extended from the wrists to the heels, and further supported by cartilaginous spurs starting from the fore limbs; but, whilst in the Flying Squirrels this spur springs from the wrist itself, in the Anomalures it projects from the elbow, and thus produces a still greater extension of the membrane. The ears are well developed, the eyes large, and the general aspect both of head and body completely squirrel-like. Six species of this family have been described, all from the West Coast of Africa. One of them occurs in the island of Fernando Po. The species figured (Anomalurus fulgens) is from the Gaboon. It is a handsome little creature, of a bright reddish colour, paler below, and having a small white spot between the ears. Its length is fourteen inches, and its tail is seven inches long. In some of the other species the tail is as long as the body. Of the habits of these animals little is positively known, but they are said to feed upon fruits. They probably resemble the Flying Squirrels in their general mode of life.

FULGENT ANOMALURE (From the Proceedings of the Zoological Society).

MOLAR TEETH OF THE ANOMALURE.

FAMILY III.—HAPLODONTIDÆ.

This is another small family, smaller even than the preceding one, for it includes only a single known species, limited in its range to the western coast of North America. This is the Sewellel, a little Rodent, first observed by the American travellers, Lewis and Clarke, in 1805 or 1806, described in 1814 by Rafinesque under the name of Anisonyx rufa, and afterwards, in 1829, by Sir John Richardson, as the type of a new genus, as Aplodontia leporina. This generic name has been corrected, in accordance with its derivation, by more recent writers, to Haplodon, from which the name of the family has been formed.

In this animal there are five molars in the upper and four in the lower jaw; the first upper molar is very small, and all these teeth are rootless, simple, and prismatic, the surface of each tooth being surrounded by a mere border of enamel. The skull is very flat, very wide behind, and furnished with large zygomatic arches; between the orbits and in front it is much contracted, and there are no post-orbital processes. In the lower jaw the angular portion is twisted so as to form a horizontal ridge. The body is stout and clumsy, the tail very short, and the claws of the fore feet (which are five-toed, as well as the hind ones) are very powerful; in fact, as Dr. Coues says, “The whole organisation, viewed externally, indicates terrestrial and highly fossorial habits.”

The SEWELLEL (Haplodon rufus) is about a foot long, with a tail of an inch or an inch and a half; its colour is brownish, with an intermixture of black hairs, lighter and more greyish below. The whiskers, claws, and upper surface of the feet are whitish, and the incisor teeth yellow. It inhabits the Washington and Oregon territories, from the Rocky Mountains to the shores of the Pacific, and extends also into the southern portions of British Columbia and the upper parts of California.

The Sewellel is described as having very much the same habits as the Prairie Dog, living in society, burrowing very readily in the ground, and feeding on roots and berries. Their companies, however, seem to be much smaller than those of the Prairie Dog, and they are said chiefly to frequent spring-heads in rich, moist places. They are described as having the curious habit of neatly cutting off some herb or plant, which, when packed in bundles, they lay out and expose to the sun to dry; this is probably for the purpose of storing for winter consumption. It seems to be uncertain whether the Sewellel is torpid during the winter, but probably in this respect it varies according to local conditions or the coldness of the seasons. Dr. Suchley believes that the Sewellel has several litters of young during the season. The Indians trap them, and esteem them very highly as food. Cloaks or blankets are made of their skins, which are sewn together with fibres derived from the sinews of the Elk and Deer. A robe described by Sir John Richardson was composed of twenty-seven skins.

FAMILY IV.—CASTORIDÆ.

Unlike as the Beaver may be to a Squirrel, it yet presents many characters which prove that its nearest affinity is to the animals which compose the group Sciuromorpha. This relationship has indeed been overlooked by many zoologists, but Mr. Alston and Mr. Allen have clearly shown that Professor Gervais was right in placing the CastoridÆ in close juxtaposition with the Squirrels. The peculiarities which make the apparent discrepancy so striking are indeed chiefly those by which the Beaver is adapted to an aquatic life.

MOLAR TEETH OF THE BEAVER.

The Beaver, which is the sole living representative of this family, is a more powerful animal than any of the preceding, and his incisor teeth and the means of working them are especially well developed. The head is large and the skull massive, and furnished with a distinct median (sagittal) crest for the insertion of the strong muscles which move the lower jaw. There are no post-orbital processes. There are four molars on each side in each jaw, and these are nearly similar in size and structure; but, contrary to what we have seen in the preceding groups, the first molar is the largest, and the others diminish in size towards the hinder end of the row. The series of teeth in the two sides of the mouth converge toward the front; and the teeth themselves, which are for a long time rootless, and only close up to form a simple root when the animal grows old, show three folds or loops of enamel on one side, and a single fold on the other: the three folds entering from the outer surface of the tooth in the upper jaw, and from its inner surface in the lower.

The general form is stout and heavy, especially in the hinder parts; the tail is of moderate length, broad, flattened, and covered with a scaly skin; the feet are all five-toed, the fore pair considerably smaller than the hinder, but all well furnished with claws, and the hinder pair fully webbed to the extremities of the toes. The wrist has a large ossicle, in addition to those usually composing that part of the body. The eyes are small, have the pupil vertical, and are furnished with a nictitating membrane; the ears are small and short, and their antitragus can be so applied to the head as almost entirely to close the auditory aperture; and the nostrils are also so arranged as to be capable of closing.

BEAVER.

The Beaver is usually about two feet and a half long, and is, therefore, one of the largest of the Rodentia, except the Capybara. The tail, which is flattened above and below, and of an elongated oval form, measures about ten inches. The muffle is naked; the ears scaly; the soles of all the feet are naked, and their upper surfaces clothed with hairs; and the second toe of the hind feet is usually furnished with a double claw, the additional one being placed beneath the other. The general colour of the fur is reddish-brown on the upper surface, lighter and greyish below. The colour varies a little in different individuals, and appears to become darker, or even blackish, in northern localities. White or pied individuals are not uncommon. The Beaver appears to increase in size for some years after it has attained maturity. Mr. Allen says that in America “two-year-old Beavers generally weigh about thirty-five to forty pounds, while very old ones occasionally attain a weight of upwards of sixty.” The size of the skull seems to increase throughout life; the thickness and density of the bones also increase, and the ridges for the attachment of the muscles become stronger in old individuals.

The Beaver is, or has been, distributed generally over all the northern parts of the Northern hemisphere, especially in the forest regions. Formerly it ranged over the whole of Europe, including the British islands, where there is historical evidence of its former existence, besides the skulls and bones which have been found in various places, but especially in the Fen lands. At present the animal appears to be completely exterminated in the southern parts of Europe from France southwards, with the exception of a small colony on the Rhone, which we believe is still in existence; and only a very few individuals survive in Germany, where they are found on a tributary of the Elbe, and in one or two other places. In some parts of Poland, Russia, and Austria, and in the Scandinavian peninsula, they still, to a greater or less extent, hold their ground; and in Asia they abound about the rivers of Siberia, and in the streams which flow into the Caspian Sea. In North America Beavers formerly abounded from Texas, and, according to manuscript evidence cited by Mr. Allen, even from Mexico, northward to the extreme limit of forest growth, and from the Atlantic to the Pacific coast. The constant pursuit to which the animals were subjected, in consequence of the demand for their skins, greatly diminished their numbers, and in many localities altogether exterminated them; but they still occur over a very large extent of the North American continent, especially in the western territories, where they are even abundant in some of the wilder parts.

In the preceding statements we have spoken of the Beaver as forming a single species; but it has long been a moot question with zoologists whether the Beavers of the Old and New Worlds were or were not specifically identical. The external differences are very slight, and those observed in the skull, upon which most stress has been laid, do not appear to be of sufficient importance for the separation of the animals as distinct species. They consist chiefly in the greater breadth of the anterior portion of the skull, including the inter-orbital space; the extension farther back of the nasal bones, the greater size and depth of the basilar cavity and the more anterior position of the auditory bullÆ, in the European Beaver; but the examination of large series of specimens has proved that the skulls from both hemispheres present many exceptions, in which one or more of the peculiarities which they ought to exhibit do not occur: a circumstance which of necessity greatly invalidates the distinction founded upon such characters. Dr. Ely sums up the results of an extended investigation in the following words:—“The extremes of difference, in their aggregate, on the one side and on the other, are sufficiently striking to justify us in regarding them as varieties of one and the same species; while the want of constancy in these peculiarities suggests the inference that these variations are due to long separation of the races, and to accidental causes, rather than to original diversity of the stock.” The Beaver may thus be regarded as a species with two geographical forms (varieties or sub-species), viz., Castor fiber, var. europÆus, and Castor fiber, var. canadensis.

So much has been written upon the habits of the Beaver, that the following short statement will suffice to give the leading facts in the natural history of the animal, the accounts of the marvellous sagacity of which, given by the older writers, have, perhaps, invested it with an exaggerated interest.

In populous countries the Beaver is contented, like the Otter, with a long burrow for his residence; but in the wilder regions of Siberia and North America his dwelling-place is a much more complicated affair. But even in these regions, according to some authorities, a certain number of Beavers—always males—show a lazy unwillingness to take part in the common labours of the colony, and these, as idlers, are expelled from the community, often with rather severe treatment, and then take up their abode by themselves in holes, which they dig out in the banks of rivers, whence they are called “terriers.” On the other hand, it would appear that the building instinct which is so remarkably manifested by the Beaver is not always extinct even in those which inhabit populous countries, for we have a most interesting account from M. Meyerinck of the construction of a lodge, and even of a dam, by the colony of Beavers on a tributary of the Elbe.

In North America, from which we have the fullest accounts of the habits of the Beavers, these animals select for their habitation some small stream running through a locality well covered with trees, especially willows, birches, and poplars, upon the bark of which they chiefly feed. These trees they cut down with their powerful incisor teeth, usually selecting those from the thickness of a man’s arm to that of his thigh, but sometimes even felling trunks eighteen inches in diameter. The operation, which at first sight would seem to be a rather difficult one for an animal like the Beaver to perform, is effected by gnawing all round the trunk for a certain distance, and gradually working deeper and deeper into its substance in the middle of the part attacked, until at length the tree stands upon quite a slender piece of wood, with the trunk both above and below this tapered off into the form of two cones, united by their apices. The work is done as sharply and neatly as if the wood had been cut away by a chisel; and the animals are said to have the sagacity to weaken the trunk more on the side that looks towards the water than on the opposite side, by which means, when it falls, it will generally do so in the direction of the water, which materially facilitates the further operations of the Beavers. The quantity of trees cut down by them in this way is very great, so that in the neighbourhood of a Beaver encampment the ground is everywhere full of the stumps which they have left.

These tree trunks are then cut up into lengths of five or six feet, which, after their bark has been stripped off and eaten, are employed in the formation of a lodge, to serve as a shelter for the company of Beavers forming it. Access to the lodge is obtained by means of several subterranean passages, which always open under water, and lead up into the chamber occupying the interior of the lodge. The lodge is usually of an oven-like shape, and is built close to the edge of the water; its walls are very thick, and composed of the above-mentioned trunks of trees, plastered over with mud, clay, &c., mixed with grasses and moss, until the whole fabric measures from twelve to twenty feet in diameter, and forms a hill some six or eight feet high. The larger lodges are in the interior about seven feet in diameter, and between two and three feet high; and the floor of this spacious chamber is covered with fine chips of wood, grasses, and the soft bark of trees, which serve to form the beds of the occupants. Occasionally the lodges are said to contain store-rooms. In front of the lodge, according to Audubon, the Beavers scratch away the mud of the bottom until they make the water deep enough to enable them to float their pieces of timber to this point, even when the water is frozen; and, communicating with this, a ditch surrounds the lodge, which is also made so deep that it will not readily freeze to the bottom. Into this ditch, and the deep water in front of the lodge, the passages by which access to the water is obtained always open, and thus the inhabitants can at any time make their way out when their business requires them to do so. In the neighbourhood of the lodge the timber cut into lengths, as above described, is piled up, so as to furnish a supply of food as it is required; and the pieces of timber, after being stripped of their bark, are usually employed by the Beavers either in repairing their lodges or in constructing or strengthening the dams which they very frequently throw across the streams haunted by them. These dams, which are destined to keep the water of variable streams up to the necessary height for the convenience of the Beaver, are wonderful pieces of work, and almost justify the marvellous stories told of its intelligence and sagacity by the older writers. They are often of great length—sometimes 150 or 200 yards and more—and run across the course of the brook inhabited by the Beavers—sometimes in a straight line, sometimes in a curved form, according to peculiarities in the ground or the stream, and the exigencies of the engineers. They are composed, like the lodges, of lengths cut from the trunks and branches of trees, filled in with smaller sticks, roots, grasses, and moss, and all plastered with mud and clay in a most workmanlike manner, until the whole structure becomes quite water-tight. Their height is from six to ten feet, and their thickness at the bottom sometimes as much as double this, but diminishing upwards by the slope of the sides until the top is only from three to five feet wide. These dams convert even small rivulets into large pools of water, often many acres in extent; and in districts where Beavers abound these pools may occupy neatly the whole course of a stream, one above the other, almost to its source. Their use to the Beavers, as constantly furnishing them with a sufficiency of water in which to carry on their business, and especially to float to their lodges the tree trunks necessary for their subsistence, is easily understood; but it is a more remarkable circumstance that by this means the Beavers exercise a considerable influence upon the external appearance of the locality inhabited by them, which may persist even long after they have themselves disappeared. In and about the pools the constant attacks of the Beavers upon the trees produce clearings in the forest, often many acres in extent; at the margins of the pools the formation of peat commences, and under favourable circumstances proceeds until the greater part of the cleared space becomes converted into a peat-moss. These peaty clearings are known as Beaver-meadows, and they have been detected in various countries where the Beaver is now extinct.

As in the case of the majority of Rodents, the chief activity of the Beaver is nocturnal; and it is only when driven from its lodge by a high flood, or in the wildest and most sequestered localities, that it goes about during the day. It swims quickly, but entirely by the agency of the hind feet, the fore feet being used chiefly for carrying and building operations, and for conveying the food to the mouth. Before diving, it is said to slap the surface of the water with its tail, producing a sound that may be heard at a considerable distance. On land it sometimes travels a good way in the warm season, and is then stated to indulge in a change of diet, feeding upon roots and fruits, and sometimes upon corn. The roots of the water-lily (Nuphar) are also said to constitute part of its food. The Beaver is hunted—but less now than in former years—for the sake of its skin, the soft under fur of which was much used in the manufacture of hats. It is asserted that the flesh is very good, but according to some authorities, only certain parts of it are palatable; and Audubon declares that the tail, which is regarded as a peculiarly choice morsel, closely resembles marrow, and is so rich that only those whose stomachs are incapable of being upset by greasy food can eat more than a very little of it.

The Beaver has been hunted not only for its fur, but also, and from time immemorial, for the sake of a peculiar secretion produced by it, which, under the name of Castoreum, has been for many centuries a highly-esteemed medicament. This substance is secreted in a pair of glandular pouches, situated in the inguinal region of the male Beaver; and it would seem that it was almost entirely in order to procure these that the ancients hunted this animal. Even in connection with this they had wonderful tales to tell of its sagacity: as how that, when it was pursued and found itself unable to escape, it would throw itself upon its back, as if to invite the hunter to take what he wanted and spare its life. Nay, some ancient writers seem to have believed that the Beaver would go the length of biting off its own castoreum glands, and leaving them for the hunter to pick up! Castoreum contains some volatile oil and resin, and a peculiar crystallisable substance called castorine; it is used in medicine as a stimulant, and seems to act especially on the nervous system, but is not much employed nowadays. Its odour, which appears to spread over a considerable space, is described as being very attractive to other Beavers. Audubon states that it is used for this reason as a lure by the American trappers.

THE MOUSE-LIKE RODENTS—MYOXIDÆ—Characteristics—THE DORMOUSE—Description—Habits—Activity—Food—Winter Condition—THE LOIR—THE GARDEN DORMOUSE—LOPHIOMYIDÆ—How the Family came to be Founded—THE LOPHIOMYS—Milne-Edwards’ Opinion—Skull—General Form—Habits—MURIDÆ—Number of Species—Characteristics—Variety of Forms—Distribution—The Murine Sub-Family—THE BROWN RAT—History—Fecundity and Ferocity—Diet—At the Horse Slaughter-houses of Montfaucon—Shipwrecked on Islands—Story of their Killing a Man in a Coal-pit—In the Sewers of Paris and London—THE BLACK RAT—THE EGYPTIAN RAT—THE COMMON MOUSE—Habits—Destructiveness—Colours—THE LONG-TAILED FIELD MOUSE—Description—Food—THE HARVEST MOUSE—Description—Habits—In Winter—Agility—Their Nest—THE BANDICOOT RAT—THE TREE RAT—THE STRIPED MOUSE—Allied Genera—THE WHITE-FOOTED HAPALOTE—The American Murines—THE WHITE-FOOTED, OR DEER MOUSE—THE GOLDEN, OR RED MOUSE—THE RICE-FIELD MOUSE—THE AMERICAN HARVEST MOUSE—THE FLORIDA RAT—Description—Their Nest—Food—Mother and Young—THE BUSHY-TAILED WOOD RAT—THE COTTON RAT—THE RABBIT-LIKE REITHRODON—THE HAMSTERS—Characteristics—Appearance—Distribution—Burrows—Disposition—Food—Habits—THE TREE MICE—THE BLACK-STREAKED TREE MICE—THE GERBILLES—Characteristics—Habits—Other Genera—THE WATER MICE—Characteristics—Species—THE SMINTHUS—THE VOLES—Characteristics—THE WATER VOLE—Appearance—Distribution—Food—THE FIELD VOLE—THE BANK VOLE—THE SOUTHERN FIELD VOLE—THE SNOW MOUSE—THE ROOT VOLE—THE MEADOW MOUSE—THE PINE MOUSE—THE MUSQUASH, MUSK RAT, OR ONDATRA—Distinguishing Features—Habits—His House—THE LEMMING—Description—Food—Habits—Disposition—Their Extraordinary Migrations—Other Lemmings—THE ZOKOR,

SECTION II.—MOUSE-LIKE RODENTS (MYOMORPHA).

THE Myomorphic, or Mouse-like group of Rodents, includes a much greater variety of forms than the preceding, and the number of species is also very great. We find in it arboreal, terrestrial, and aquatic species; and in the second of these categories some presenting almost every variety of habit which the Rodent type is capable of assuming. Naturally the families and sub-families into which it is divided are rather numerous. Mr. Alston distinguished seven family groups, the first of which is the MyoxidÆ.

FAMILY V.—MYOXIDÆ.

The Dormice, which constitute this family, have generally been regarded as nearly related to the Squirrels; and certainly, although they fall under the definition of the Myomorphic section, they have a plain affinity to the SciuridÆ. In form they are Squirrel-like, and the tail is long and hairy, although not so bushy as in the true Squirrels. They have four molars on each side in each jaw (see figure), the front one in each series being smaller than the rest. All these teeth are rooted, and their crowns show transverse folds of enamel. The frontal bones are much narrowed; the fore limbs are small, with the thumbs rudimentary and furnished with a small flat nail; and the hind feet have five toes. The Dormice differ from all other Rodents by having the intestine entirely destitute of a cÆcum. They are confined to the Eastern hemisphere, and chiefly to its temperate and colder regions; although a species of Myoxus, and some forms on which a special genus (Graphiurus) has been founded, inhabit Africa. The number of known species is only about a dozen.

MOLAR TEETH OF THE DORMOUSE.

The common DORMOUSE (Myoxus avellanarius) is an elegant little creature, about three inches long, with a somewhat bushy, cylindrical tail, two inches and a half in length. Its fur is of a light reddish-tawny colour above, becoming paler and yellowish on the lower surface. On the throat there is a small whitish mark. It is widely distributed in Europe, ranging from Britain and Sweden in the north to Tuscany and Northern Turkey in the south. Generally it is more abundant in southern than in northern countries, but in the south of France it is less common than either of the other two European species. Eastwards it does not extend beyond Galicia, Hungary, and Transylvania.

DORMOUSE.

The Dormouse is nocturnal in its habits. During the day it sleeps in its nest or in some snug retreat, and at night comes forth in search of its food, which consists of nuts, acorns, seeds, berries, and the buds of trees and shrubs. It is particularly fond of the nuts of the common hazel, whence its specific name, and the name of “Haselmaus,” which it bears in Germany; these nuts it is said to pierce and empty without plucking them or taking them out of their cups. The Dormouse lives in small societies in thickets and hedgerows, where it is as active in its way amongst the bushes and undergrowth as its cousin the Squirrel upon the larger trees. Among the small twigs and branches of the shrubs and small trees the Dormice climb with wonderful adroitness, often, indeed, hanging by their hind feet from a twig in order to reach and operate on a fruit or a nut which is otherwise inaccessible, and running along the lower surface of a branch with the activity and certainty of a Monkey. Detached articles of food are held up to the mouth by the fore paws, after the fashion of a Squirrel. Towards the winter the Dormouse becomes exceedingly fat, and having collected a small store of food, makes for itself a little globular nest, composed of small twigs, leaves, pine-needles, moss, and grass, and within this, coiled up into a ball, passes into a torpid state.

Nevertheless, the winter sleep is not wholly uninterrupted; on mild days the Dormouse wakes up for a time and takes a little of its stored-up food. The female produces usually about four young, in the spring according to Professor Bell, in August according to Brehm; but the former writer thinks that in some cases two broods are produced in the year, as he has received from the same locality in September a half-grown Dormouse and three very young ones, evidently not more than a fortnight or three weeks old.

Of the other common European species, the LOIR (Myoxus glis) is found only in southern regions, its range extending from Spain to Southern Russia, and passing into the neighbouring parts of Asia. It is considerably larger than the Dormouse, measuring rather more than six inches in length, and has a bushy tail, in which the hairs are arranged in two rows, as in that of the Squirrel. The habits of this species are like those of the Dormouse. Fruit constitutes a portion of its diet, and it is said also to destroy and devour small birds and other animals. The Loir is a very voracious feeder, and becomes exceedingly fat in the autumn. By the ancient Roman epicures it was regarded as a dainty morsel, and they spared no pains to fatten it for the table. It sleeps during the day, and hibernates in some hole in a tree or in the ground, and the nest is formed in the former situation. The female usually produces about six young.

GARDEN DORMOUSE.

The GARDEN DORMOUSE, or LEROT of the French (Myoxus nitela), is common all over the southern and western parts of the Continent, extending northwards through Germany into the Baltic provinces of Russia. It is a little smaller than the preceding species, which, however, it resembles in its general habits; but it dwells commonly in gardens, and feeds on fruits, often doing much damage to the choicer varieties. It is a lighter and more active animal than the Loir, and is said to be even more predaceous in its habits. The female produces from four to six young, sometimes in a beautifully-made nest of her own, sometimes in the deserted or usurped nest of a Blackbird or Thrush, or in that of a Squirrel.

FAMILY VI.—LOPHIOMYIDÆ.

The importance of an animal in the zoological system by no means depends either upon its size or on its abundance in the world; its rank in the classification is decided solely by peculiarities of organisation which distinguish it more or less from its fellows; and in many cases the creatures which are regarded with the most interest by the naturalist are those which seem most to withdraw themselves from general observation. A single genus, perhaps containing only one or two species, may, by a singular combination of characters, be so completely isolated from all the recognised allied groups that it cannot be placed in any of them, and accordingly a distinct family, possibly even an order, has to be established for its reception. Sometimes subsequent discoveries add to the number of species forming the group thus set up, and in this way the prescience of its founder is confirmed. Sometimes the group remains in its original condition, leaving us, according to circumstances, to regard the anomalous creatures of which it is composed either as a special development of their general type, or as the residue of a group which may have presented a greater variety of forms at some past period of the earth’s history.

SKULL OF LOPHIOMYS.

The latter is perhaps the case with the curious little Rodent which alone forms the present family, of which its original describer, M. Alphonse Milne-Edwards, writes as follows:—“In its general aspect it somewhat resembles certain Opossums, and like these it is pedimanous;[52] but these are the only analogies it presents to the Marsupials, and in its dental system, as also in the rest of its organisation, we easily see that it belongs to the order Rodentia. It differs, however, from all the members of this group by characters of considerable importance; I may even say that, by some peculiarities of structure it departs from all other Mammals, and that we find in it anatomical arrangements of which we have hitherto had examples only in the class of Reptiles.” After an exhaustive discussion of the characters of this curious little animal, M. Milne-Edwards comes to the conclusion that it is most nearly related to the members of the following family, and especially to the Hamsters, although he found it impossible to unite it with them. In this course he has been followed by other writers.

LOPHIOMYS.

The general construction of the skull is the same as in the MuridÆ, but from the temporal ridges thin plates are developed, which bend downwards, and articulate with similar plates springing from the malar bones, and thus completely arch over the temporal fossÆ after a fashion only met with in certain reptiles, and especially in the Hawksbill Turtle (Chelone caretta). The whole upper surface of the skull is covered with minute but perfectly definite granules, arranged with much regularity, and these, which occur in no other Mammal, give the skull a very peculiar aspect, such as may be seen in some fishes. As in the MuridÆ, there are three molars on each side in each jaw, and these are rooted and strongly tubercular; the foremost in each series having three and the others each two ridges. Without entering in detail into the peculiarities described at great length by M. Milne-Edwards, we may say that in its general structure, and especially in that of the skeleton, the animal is murine, but with a very important distinction, namely, that the collar bones, which are well developed in the Rats and their allies, are here reduced, as in the Hares and Rabbits, so as to form only two small bony styles freely suspended among the muscles, and that the first toe in the hind feet, although not very long, is so attached as to be opposite to the rest, thus converting the organ into a prehensile hand which the animal uses freely in climbing. The cÆcum is small.

In its external characters this animal is as remarkable as in its anatomical structure. In general appearance, as stated by its describer, it has much resemblance to a small Opossum, but the bushy tail and the peculiar arrangement of the hair on the body are met with in no Marsupials. The head is small; the general form stout; the limbs short, and the hind ones not much longer than their fellows; and the ears are of moderate size and sparingly clothed with hair. The prevailing colour is blackish-brown, but a triangular spot on the forehead, a streak under each eye, and the tip of the tail, are white; and the long hairs which clothe the body and tail are dark only in the middle, the base and tip being white, as are also a great quantity of finer and shorter hairs which form a sort of under fur. But the chief peculiarity of the coat is to be found in the arrangement of the hairs of the body. The long hairs of the middle of the back and tail, some of which are nearly three inches in length, are capable of being raised into a nearly upright position, forming a sort of crest which gives the animal a very peculiar aspect, and this crest is separated from the pendulous hair of the flanks by a sort of furrow clothed with very peculiar hair of a greyish-tawny colour. These hairs are unlike any others known to occur among Mammals. The apical part is of the ordinary construction; but the following portion down to the base is “very rugose, and presents a spongy aspect, due to the interlacing, and, so to speak, felting of a multitude of epidermic filaments emanating from radiate cells, which constitute a perfect network of irregular meshes. Within the sort of sheath thus formed longitudinal filaments which break up into bundles of fibrils are to be seen.”

Very little is known as to the habitat of this animal, which M. Milne-Edwards has named Lophiomys Imhausi, the former name referring to the crested character of the back, the second commemorating the person who first brought the creature to the notice of naturalists. M. Imhaus, stopping for a few hours at Aden on his way home from RÉunion, saw a living specimen of this Rodent in the possession of a negro from whom he bought it, but could learn nothing as to its origin. He inferred, however, that it had not been brought very far, and that its native country was either Southern Arabia, or some region in Abyssinia, or Nubia, on the other side of the Red Sea. This specimen was brought to France, and lived for about a year and a half in the Garden of Acclimatization in the Bois de Boulogne, where it fed upon maize, vegetables, and bread, slept during the day, and climbed with ease upon chairs and other convenient objects by the aid of its hinder hands. It never took its food in the fore-paws to carry it to the mouth as so many Rodents do. When irritated it elevated the crest right down to the end of the tail, and defended itself by biting vigorously.

It is doubtful whether the Lophiomys inhabits Arabia, but it is found in the neighbouring parts of Africa. Professor Peters described the skull of the animal as representing a new generic type under the name of Phractomys Æthiops. His specimen was obtained by Dr. Schweinfurth from the tombs of Maman, north of Kassala, in Upper Nubia. A third specimen has been brought from Keren in the Bogos country, and a fourth from the Erkanid mountains between Suakim and Singat.

MOLAR TEETH OF THE BLACK RAT.

FAMILY VII.—MURIDÆ.

We come now to the largest and most typical family of the Rodents: that, namely, which includes the Rats and Mice and their numerous allies. Mr. Wallace estimates the number of known species at 330, which is probably within the mark. All these forms agree in the following characters:—The lower incisors are compressed; the molars are usually three in number on each side in each jaw, in one genus only two in the lower or in both jaws, and in another four in both jaws. They are rooted or rootless, tubercular or flat, with folds of enamel; the malar bone is short and slender, generally reduced to a mere splint between the maxillary and squamosal processes of the zygomatic arch; the thumb is rudimentary, but often furnished with a small nail; and the tail is generally scaly, with a few scattered hairs, densely hairy only in a few species.

As might be expected in so large an assemblage of species, the variety of forms is very great among the MuridÆ, but broadly, the common Rats and Mice, which are only too well known to most of us, may serve as characteristic types of the whole series. The family, however, includes jumping forms, swimming forms, arboreal forms, and burrowing forms, in which the peculiarities of the life-habits are very distinctly indicated by the external appearance of the creatures. In their distribution the MuridÆ are almost absolutely cosmopolitan, the family being represented in every part of the world, with the sole exception of the islands of the Pacific Ocean. Australia possesses about thirty species of the family. New Zealand, at the time of its discovery, harboured a Rat, known as the Forest Rat, or Maori Rat, which was a favourite article of food with the natives, and is now almost extinct. It was proved by Capt. Hutton to be identical with the Black Rat (Mus rattus), and was probably introduced by the ancestors of the Maoris. Certain species also, such as the common Brown Rat and Mouse, are now perfectly cosmopolitan in their distribution, having accompanied man in all his migrations on the surface of the globe.

BROWN RAT.

The Rat and Mouse form the types of a great sub-family, MURINÆ, which have the molars rooted and tuberculate when young, the infra-orbital opening high and perpendicular, widest above, and the lower root of the zygomatic maxillary process flattened into a perpendicular plate. They possess no cheek-pouches, have the fore and hind limbs approximately equal in length, the thumb rudimentary, and the tail nearly naked, covered with scaly rings. The genus Mus, to which our household pests belong, includes upwards of one hundred species, scattered over most parts of the Eastern Hemisphere, and living sometimes chiefly in the neighbourhood of human habitations, granaries, &c., where they often feed indifferently upon animal and vegetable substances, sometimes in the open country, and feeding almost exclusively upon the latter. The common BROWN RAT (Mus decumanus), sometimes called the Norway Rat, which is almost too well known to need description, is not a native of Great Britain, but was certainly introduced there by commerce, probably from some southern or eastern country—perhaps, as Pennant thinks, from the East Indies. Haunting ships in great numbers, it has now been introduced into all parts of the world, and it is quite impossible to ascertain its original habitat. It was known in Asia long before it made its appearance in Europe; and its passage into Russia is fixed by Pallas in the year 1727, when, he says, after an earthquake it swam across the Volga from the countries bordering the Caspian. Its first appearance in France and England is said to have occurred about the middle of the last century.

BLACK RAT.

From its great fecundity and determined ferocity of disposition, the Brown Rat has become a great pest wherever it has taken up its abode. “It digs,” says Professor Bell, “with great facility and vigour, making its way with rapidity beneath the floors of our houses, between the stones and bricks of walls, and often excavating the foundations of dwellings to a dangerous extent. There are many instances of their fatally undermining the most solid mason-work, or burrowing through dams which had for ages served to confine the waters of rivers and canals.” It is almost impossible to keep them out of our houses, and, once in, there is no end to the mischief they do. Their ferocity is very great; and although they will, if possible, retreat from a powerful enemy, they will fight in the most savage fashion when they cannot escape.

Although not averse to a vegetable diet—as those who have to do with corn and seeds, whether in the field or the store-house, know to their cost—the Brown Rat evinces a decided preference for animal food, which he consumes of all kinds and in all states. The case of the horse slaughter-houses of Montfaucon, near Paris, is well known; here, the carcases of all the Horses killed during the day, sometimes to the number of thirty-five, would be picked to the bone by the next morning; and one main argument against the removal of the establishment to a greater distance from the city was that these swarms of ferocious vermin would be left without means of support, and would become a complete pest in the neighbourhood. That such an apprehension was not unfounded is proved by several instances recorded of the escape of Rats from wrecked ships upon small islands. In the course of a few years they exterminated every other living thing. Professor Bell, on the authority of the late Mr. Robert Stephenson, relates the following instance of the extreme ferocity of the Rat when driven by hunger:—“In a coal-pit,” he says, “in which many Horses were employed, the Rats, which fed upon the fodder provided for the Horses, had accumulated in great multitudes. It was customary in holiday times to bring to the surface the Horses and the fodder, and to close the pit for the time. On one occasion, when the holiday had extended to ten days or a fortnight, during which the Rats had been deprived of food, on re-opening the pit, the first man who descended was attacked by the starving multitude, and speedily killed and devoured.” Stories are also told, with what truth we do not know, of the occurrence of similar catastrophes in the sewers of Paris and London, where, as is well known, Rats abound.

The Brown Rat breeds several times during the year, and produces as many as ten, twelve, or fourteen young ones in a litter. Its general length is about nine inches. It may be distinguished from the old English Rat, which it has displaced in most localities, by its greyish-brown colour and by the comparative shortness of its ears, which, when pressed down, do not reach the eye.

The BLACK RAT (Mus rattus), or old English Rat, as it is sometimes called, agrees closely in its habits with the Brown Rat. It is smaller than the Brown Rat, measuring only about seven inches in length, but has a comparatively much longer tail and larger ears, which, when pressed forward, cover the eyes. Its colour above is greyish or brownish-black, and the lower parts are dark ash colour. Although the Black Rat has generally been compelled to give way before its larger and more vigorous competitor, it is still widely dispersed, but not in such numbers as formerly, in Europe. Its native country was probably Southern Asia. Nearly allied to it, if indeed specifically distinct, is the EGYPTIAN RAT (Mus alexandrinus). Both these Rats are said to keep more to the upper parts of houses than the Brown Rat.

Although the true Mice are very nearly allied to the Rats, of which they are copies on a small scale (and some of them, at any rate, are as destructive in their way as their larger relatives), they do not excite by any means the same sentiments of disgust with which Rats are generally regarded; ladies, indeed, will sometimes scream at the mere sight of a Mouse, but most of them will admit that, apart from its predatory habits, it is an elegant little creature. The COMMON MOUSE (Mus musculus) seems to be as completely associated with man as the Rat, and has accompanied him in his wanderings to all parts of the world. It is, however, said not to occur in the Sunda Islands. Of its general appearance and habits we need say nothing; they are too familiar to need description. But besides haunting our houses, the Mouse takes up its abode in the rick-yard, and here its devastations are often very serious. The Mice live in the ricks, through which they make passages in every direction, and their fecundity is so great that several bushels of Mice are often destroyed during the removal of a single rick. The Mouse breeds all the year round, and usually produces five or six young at a birth, so that its rapid increase under favourable circumstances is easily understood. Several varieties of the species are well known, especially the Albino form, or White Mouse, which is such a favourite pet with boys. The Common Mouse in England is sometimes patched with white, and we sometimes see in the shops Pied Mice, which are said to be of Indian origin. A pale buff variety is also sometimes met with; and during the removal of a rick some years ago, it was found to be infested by a breed of Mice with a naked wrinkled skin, to which the name of Rhinoceros Mice was given at the time.

Besides these more or less domestic species, there are in Britain two other representatives of the genus Mus, which do not generally frequent houses. One of these is the LONG-TAILED FIELD MOUSE (Mus sylvaticus), sometimes called the Wood Mouse, an exceedingly pretty little creature, rather larger than the Common Mouse, and having a proportionally longer tail. It measures about four inches in length, and the tail is about as long as the body; its colour is yellowish or yellowish-brown on the upper surface, whitish beneath; and the tail is brown above and white beneath. This species is found all over the temperate parts of Europe and Asia, living in the fields and gardens, where it takes up its abode, either in some small cavity under the root of a tree, in the deserted runs of the Mole, or less commonly in a little burrow excavated by its own labour. It feeds chiefly upon grain and seeds, of which it lays up a considerable store for winter use in its subterranean dwelling, and in this way does considerable damage to the crops. The Field Mouse does not, however, strictly confine itself to a vegetable diet, but under circumstances of privation will attack and devour smaller and weaker animals, not even sparing its own species. It breeds more than once in the year, and produces from seven to ten young in each litter. It is easily tamed, and soon becomes familiar.

HARVEST MICE.

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LARGER IMAGE

The remaining British species, the HARVEST MOUSE (Mus minutus), is the smallest of the British quadrupeds, with the exception of the Lesser Shrew (Sorex pygmÆus). The Harvest Mouse is to be found in most parts of England. It also occurs in Scotland as far north as Aberdeenshire; and in Ireland, but very rarely. On the Continent its range extends over nearly the whole of Europe, from Russia in the north to Italy in the south. It is well known in Siberia, and occurs abundantly in the steppes near the Caucasus.

The total length of this pretty little Mouse is about five inches, of which nearly one-half is made up of the tail. In it the eyes are less prominent than in the common Field Mouse, and the ears considerably shorter in proportion. Its colour on the upper surface is bright reddish-brown, and below pure white, the two colours being sharply separated. During the summer, the Harvest Mouse associates with the other Field Mice in corn-fields, and with them is very frequently carried in the sheaves of corn to rick-yards and barns, where it then takes up its abode for the autumn and winter, and, like other Mice, multiplies very rapidly, and no doubt does a good deal of mischief. The less fortunate individuals who are left behind in the fields retreat to little burrows for protection from the inclemency of the winter, which they pass in a state of at least partial torpidity; and to provide against exigencies they lay up in their dwellings a small store of food, to which they can have recourse when a fine day recalls them for a time to activity. Those which have been introduced into ricks and barns are, of course, liberally provided for, and they show their gratitude by remaining awake all the winter, as if on purpose to consume their abundant provender. In the open field their food consists of corn and the seeds of grasses and other plants, but also to a considerable extent of small insects.

In its movements the Harvest Mouse is wonderfully agile. On the ground it runs very rapidly; and it climbs upon shrubs and plants as cleverly as a Monkey, running out upon the thinnest twigs with the greatest confidence, and climbing up stalks of grasses so thin that they bend nearly to the ground with its weight. In these operations the long slender tail comes into use, as its extremity is prehensile, and can be twisted neatly round the small stalks and branches over which the little climber is making its way. From its lively habits, and the elegance of its form, the Harvest Mouse is a very interesting pet.

The Harvest Mouse breeds several times during the year, producing from five to eight or nine young at a birth, and provides for them one of the prettiest cradles formed by any Mammal. It is placed, according to the locality, upon several grass-leaves split and interwoven with the other materials, or suspended at a height of from eighteen inches to three feet above the ground, upon the twigs of some shrub or between several stalks of corn or strong grasses. It is egg-shaped, or nearly round, about the size of the egg of a Goose, and is composed externally of slit leaves of the reeds or grasses among which it is formed, each leaf being carefully divided longitudinally by the sharp teeth of the little architect into six or eight thread-like portions, which are then all woven together, so as to produce a firm structure. The interior is lined, or rather stuffed, with all sorts of soft vegetable substances, so that it has been a question with many observers how the mother could get at all the members of her family to suckle them, and how the nest could contain them all as they began to increase in bulk. The young usually remain in the nest until they can see; but as soon as they are able to provide for themselves, the mother takes them out, gives them some practical instructions in the art of living, and then leaves them to their own devices. According to Brehm, as these Mice increase in age they improve in the art of nest-building.

Besides these few species, a multitude of Rats and Mice, belonging to the same genus, occur as natives of nearly all parts of the world, but in their habits they agree in general with the British species. India harbours a considerable number, among which we may mention the BANDICOOT RAT (Mus bandicota), a large species, which inhabits the Indian and Malayan peninsulas, and is very destructive in plantations; and the TREE RAT (Mus arboreus), a native of Bengal, seven or eight inches in length, which lives partly on grain, of which it lays up stores in its nests, and partly on young cocoa-nuts, which constitute its favourite food, and in search of which it climbs the trees. This species builds a nest on cocoa-nut trees and bamboos, and occasionally makes predatory visits to the houses. The STRIPED MOUSE (Mus barbarus) is remarkable for its coloration, its ground colour being a bright yellowish-brown or reddish-yellow, adorned with several longitudinal blackish-brown streaks. This elegant Mouse inhabits Northern Africa, especially in stony places. It is very abundant in Algeria.

MOLAR TEETH OF THE HAPALOTE.

Nearly allied to the true Mice are numerous forms more restricted in their distribution, which have been formed into distinct genera. Thus Pelomys fallax, in which the incisors are grooved, the tail short, and the first and fifth toes of all the feet shorter than the three middle ones, is peculiar to Mozambique; Acanthomys, in which the fur is mixed with flattened spines, is an African genus; whilst Echinothrix, which has a somewhat similar coat, is Australian. Madagascar possesses two peculiar genera, Nesomys and Brachytarsomys, the former having some relation to the American MurinÆ, the latter remarkable for the shortness of the hind feet; and in Australia, besides the genus already mentioned, and one or two species of true Mus, we find the genus Hapalotis represented by about thirteen exclusively Australian species. These animals have the hind limbs rather long, the ears large, and the tail long and hairy, terminating in a tuft. The molar teeth also exhibit a peculiar pattern; The best known species is the WHITE-FOOTED HAPALOTE (Hapalotis albipes), an animal about the size of the Brown Rat, of a smoky brown colour, with the belly and the feet white. It inhabits New South Wales, especially in the mountainous parts. The animals of this genus were formerly regarded as allied to the South American Chinchillas and Viscachas.

The American Murines all belong to a group to which the name of Sigmodontes has been given, because their molar teeth, which in the young state have two tubercles in each transverse row (instead of three, which is the usual number in the preceding forms), when ground down by use, show some S-like patterns in the enamel folds in place of transverse ridges. The greater number of the species belong to the genus Hesperomys (Western Mouse), which is represented in both divisions of the American continent, and has been divided by authors into several sub-genera. The WHITE-FOOTED, or DEER MOUSE (Hesperomys leucopus) is perhaps the best known of all the species, and its varieties, or rather local permanent races, are distributed all over the continent of North America. The fur shows various brownish or greyish tints above; and the lower surface, with the feet up to the wrist and ankle, is snow-white. What Dr. Coues gives as the normal colour of typical specimens is a rich fawn, with a darker streak along the back: but he says that this is shown by not more than one example in six. The tail is generally white beneath. The length of the head and body is about three inches; the tail varies considerably in length. The White-footed Mouse is nocturnal in its habits, and feeds to a great extent upon corn, of which, with acorns and other nuts, it lays up stores for winter use. It lives a good deal upon trees, taking up its abode in the deserted nest of a Squirrel or of some small bird. When it constructs its own nest the little fabric is placed in a bush at from five to fifteen feet from the ground, and is very neatly constructed, usually of fine moss and strips of bark. In some localities it burrows in the ground. The GOLDEN or RED MOUSE (H. aureolus), which resembles the preceding species in form and size, has the fur of the upper surface golden-cinnamon colour, and the lower parts yellowish-white. It inhabits the Central and Southern States of the North American Union. The RICE-FIELD MOUSE (H. palustris), which has been placed in a distinct genus (Oryzomys), is a larger species, sometimes attaining the size of a small Rat. This is found in the Southern States, chiefly along the coast, and in rice-fields, where it is exceedingly abundant and does considerable damage. It is eminently aquatic in its habits. The AMERICAN HARVEST MOUSE (Ochetodon humilis) closely resembles the preceding species, but differs from them in a rather remarkable character. It has the upper incisor teeth grooved, a peculiarity which occurs also in the South American Rats of the genus Reithrodon. The American Harvest Mouse inhabits the Southern States, and extends northwards as far as Iowa and Nebraska.

The FLORIDA RAT, or Wood Rat (Neotoma floridana), is a widely distributed species in the United States, inhabiting especially the southern portion, but extending northwards as far as New York and Massachusetts. It measures from six to nine inches in length, with a tail from four to six inches long. In its coloration it presents a general resemblance to the common Brown Rat, but is brighter, especially on the sides; the lower surface is white. According to Audubon and Bachmann, the habits of this species vary considerably in different localities. These authors say that “in Florida they burrow under stones and the ruins of dilapidated buildings. In Georgia and South Carolina they prefer remaining in the woods. In some swampy situations, in the vicinity of sluggish streams, amid tangled vines interspersed with leaves and long moss, they gather a heap of dry sticks, which they pile up into a conical shape, and which, with grasses, mud, and dead leaves, mixed in by the wind and rain, form, as they proceed, a structure impervious to rain, and inaccessible to the Wild Cat, Raccoon, or Fox. At other times their nest, composed of somewhat lighter materials, is placed in the fork of a tree.” This species is very active and Squirrel-like in its habits. It feeds on grain, seeds, and fruits, and sometimes makes a meal of a Crayfish or a Frog. There are from three to six young in each litter, and two litters in the year. The young animals in very early days continue to adhere to the teats of their mother, even when she is walking about outside the nest, and even at a later period they will cling to her sides and back, after the manner of some Opossums. The female seems but little inconvenienced by this burden, and shows great affection for her family, defending them even at the risk of her own life. A nearly-allied, but smaller species, the BUSHY-TAILED WOOD RAT (N. cinerea), inhabits the western and north-western parts of America, also extending eastward to Hudson’s Bay, and southward to New Mexico and California. The COTTON RAT (Sigmodon hispidus), another inhabitant of the Southern States and Mexico, ranges southwards to Vera Cruz and Guatemala.

Besides several species of Hesperomys, South America possesses various Murine animals, which have been placed in special genera. Among these the most remarkable are those of which Mr. Waterhouse formed his genus Reithrodon, as these, although true Murines, have a very Rabbit-like character, and further present the peculiarity of having the upper incisors grooved. They have the profile much arched, the eyes large, the ears hairy, and the first and fifth toes of the hind feet very short. The tail is well clothed with hair. The RABBIT-LIKE REITHRODON (R. cuniculoides) inhabits Patagonia, where it was discovered by Mr. Darwin. It is of a yellowish-grey colour, mixed with black, with the throat and belly pale yellow, and the rump and feet white. The tail is about half the length of the head and body, dusky above, white beneath. The length of the head and body is six inches and a half. Two other species are described: one (R. typicus) from the La Plata; the other (R. chinchilloides) from the Strait of Magellan.

The HAMSTERS, forming the sub-family CRICETINÆ, are very nearly related to the true Mice and Rats, but differ from them at the first glance by their possession of large internal cheek-pouches, those organs being entirely wanting or very small in the MurinÆ. Their molars, three in number in each series, are also tuberculate when young and regularly rooted. As age advances they become more and more worn away, so as to exhibit folds of enamel. They are stoutly-built rat-like animals, generally with short tails, with the upper lip cleft, and with short limbs, of which the hinder have five, and the anterior four, toes, the thumb being represented by a small wart. The Hamsters are confined to the Old World, and chiefly inhabit the temperate parts of Europe and Asia; two or three species occur in Africa. They live generally in corn-fields, where they dig deep burrows with numerous chambers, into which they can retreat to take their repose, and in which they pass the winter, previously, however, taking care to lay up a good store of provisions in some of the chambers of their domicile.

HAMSTERS.

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LARGER IMAGE

The best known species is the HAMSTER (Cricetus frumentarius, see Plate 28), a rather pretty little beast, of about ten inches long, with bright, prominent, black eyes, short, membranous ears, and a tapering hairy tail, about two inches and a half in length. The fur, which is thick and somewhat lustrous, is usually of a light yellowish-brown colour above, with the snout, the neighbourhood of the eyes, and a band on the neck reddish-brown, and a yellow spot on each cheek; the lower surface, the greater part of the legs, and a band on the forehead are black, and the feet white. Many varieties occur. This Hamster is widely distributed, ranging from the Rhine, through Europe and Siberia, to the Obi; and in most localities where it occurs it appears in great numbers, and causes great injury to the crops. Its burrows are exceedingly spacious, and consist of numerous passages and chambers. In its temper it is exceedingly irascible, and at the same time very courageous, defending itself bravely against its enemies, and standing boldly on the defensive the moment any danger appears to threaten it. Its diet is by no means of a purely vegetable nature, but it will destroy and devour all sorts of small animals that come in its way. Besides the corn, which forms its chief winter provender, green herbage, peas and beans, and roots and fruits of various kinds, are welcome articles of diet, and in confinement it will eat almost anything.

MOLAR TEETH OF THE HAMSTER.

The Hamsters pass the winter in their burrows in a torpid state, but waken up very early in the spring, generally in March, but frequently in February. At first they do not open the mouths of their burrows, but remain for a time subsisting on the stores laid up during the preceding autumn. The old males make their appearance first, the females about a fortnight after them, the latter about the beginning of April. They then set about making their summer burrows, which are not so deep or so complicated as the winter dwellings; and shortly afterwards the sexes pair. The young are produced twice in the year, in May and July; their number varies from six to eighteen. They have teeth when first born, and their development as babies is very rapid. Their eyes open in little more than a week after birth, and in another week they begin to burrow in the ground, and then their hard-hearted parent drives them off to take care of themselves.

The other species of this sub-family generally very closely resemble the Hamster, both in appearance and manners. Most of them are found in Central Asia and Siberia, extending southwards as far as Persia and South Tartary. Cricetus songarus has been obtained at Kumaon. The recorded African species belong to two peculiar genera: they are Saccostomus lapidarius and fuscus, and Cricetomys gambianus.

Other African forms constitute the small sub-family of the TREE MICE (DendromyinÆ), which are entirely confined to the southern portion of the continent. They are characterised by having the incisors rounded and grooved in front, the infra-orbital opening not narrow below, and the coronoid process of the lower jaw very small. The ears are clothed with hairs; and the feet, which are five-toed, are furnished with long claws, which are serviceable to the little rat-like animals in climbing up the trunks of trees. The BLACK-STREAKED TREE MOUSE (Dendromys mesomelas) is a rather pretty little species, of a greyish colour, with a black line down the middle of the back. It is slender in form, with a long, scaly tail, rounded ears, and the two outer toes in each foot shorter than the rest. Steatomys pratensis, from Mozambique, is stouter in form than the preceding, and has a short, densely hairy tail; and in Lophuromys ater, from the same locality, the incisors are not grooved, and the fur is developed into fine flattened bristles.

The GERBILLES (GerbillinÆ) are distinguished from all other MuridÆ (although approached by Hapalotis) by the great length of the hind limbs, which are converted into powerful leaping organs, somewhat as in the Jerboas and Kangaroos, although not quite to the same extent. Like all the preceding forms, they have the molars furnished with roots, but not with tuberculate crowns, these being divided into transverse plates formed by separate elliptical or rhomboidal coats of enamel. The incisor teeth are narrow, the infra-orbital opening as in the MurinÆ, and the tail long and hairy. The Gerbilles are plump little animals, with a short neck, a broad head, and a pointed muzzle. The feet are five-toed, but the thumb on the fore feet is reduced to a mere wart-like process with a flat nail. They are confined to the Eastern hemisphere, and, indeed, to the African continent, the south of Asia, as far as India, and the south-east of Europe, where they live both in cultivated districts and in the driest deserts, and often occur in great numbers, when they may cause considerable damage to the neighbouring crops. They shelter themselves during the day in shallow burrows, and come forth in the evening in search of their food, which consists chiefly of grain and roots. They store up great quantities of the ears of corn in their subterranean dwellings, and in many places the poorer inhabitants search after these stores, and by digging them out procure a good supply of grain. They are very prolific, the females producing large families several times in the year.

MOLAR TEETH OF THE GERBILLE.

Several other forms of MuridÆ, with rooted molars, have been distinguished, and all are inhabitants of the Eastern hemisphere. The genera Phloeomys and Nesokia, each including a single species, form the group PHLÆOMYINÆ, characterised by having broad incisors and the molars divided by transverse plates of enamel. The characters of the skull are as in the MurinÆ. Phloeomys Cumingii is from the Philippine Islands; Nesokia Griffithii inhabits Northern India. Platacanthomys lasiurus, the only known species of the group PLATACANTHOMYINÆ, resembles a Dormouse in its form, and is nearly allied to the preceding species, but has the fur of its back mixed with long, flattened, bristle-like spines. It is a native of the Malabar coast.

SKULL OF THE WATER-MOUSE.

The WATER MICE (HydromyinÆ) are of particular interest, as being a small group, exclusively confined to the Australian region, and presenting the exceptional character among the Rodents of having only two molars on each side in each jaw. These teeth, are rooted, and divided into transverse lobes by ovate enamel lobes; the front tooth is much larger than its fellow. The Hydromys are small rat-like animals of slender form, with long tails, rather densely clothed with short hairs, and short limbs. The hind feet have much stronger claws than the fore feet, and their toes are partially webbed. Five species of this group are known from Australia and Van Diemen’s Land, where they inhabit the banks of the streams. The best known are the Yellow-bellied and the White-bellied Water Mice (Hydromys chrysogaster and leucogaster), both of which inhabit New South Wales, and the latter is also found in Van Diemen’s Land. The Sooty Water Mouse (H. fuliginosus) is an inhabitant of Western Australia.

In the SMINTHINÆ—a group which includes only the genus Sminthus, founded for the reception of a rat-like Rodent (S. vagus) first discovered in the Crimea, but now known to range from Hungary, Finland, and Sweden, through Russia to the banks of the Irtisch and Yenisei, and into Tartary (Bokhara)—we find another exceptional character of the molar teeth. There are four of these teeth on each side both above and below, the first and fourth of which are much smaller than the intervening ones. In this animal the ears are rather long and pointed, the legs are rather short, and the tail is about as long as the body, and clothed with short hairs.

TEETH OF SMINTHUS.

In the remainder of the MuridÆ, the molars, which are again only three in number on each side, are generally rootless, although occasionally the growth of the teeth stops and they close up below. The molars are composed of triangular prisms placed alternately. Two groups are thus characterised, namely, the Voles and the Zokors.

The VOLES (ArvicolinÆ), which, next to the true Rats and Mice, form the most important group of MuridÆ, are represented in the northern parts of both hemispheres. The brain-case in these animals is rhomboidal when looked at from above, the frontal region of the skull is much contracted, and the zygomatic arch stands out very far. The infra-orbital opening is as in the MurinÆ. The molars are so constructed of alternating triangular prisms that the whole margin is enclosed by deep angular folds of enamel. These are mouse- and rat-like Rodents of a rather stout build, with the limbs and tail of moderate length, or short, and the latter more hairy than in the true Murines. The ears are short, often nearly concealed beneath the fur.

The true Voles (genus Arvicola) number about fifty known species, which have been arranged by various writers under a considerable number of sub-genera, generally corresponding to differences in mode of life. Three species, representing three of these groups, are found in Britain, and may serve to illustrate the natural history of the Voles. The largest of these is the well-known WATER VOLE, or Water Rat, as it is more commonly called (Arvicola amphibius), an animal rather smaller than the Common Rat, and having, like all the Voles, the muzzle considerably blunter, and the tail a good deal shorter and more hairy. Although thoroughly aquatic in its habits, the feet of the Water Vole are not webbed; they have five toes, but the thumb in the fore feet is very short. The general colour of the fur is reddish-brown, mixed with grey on the upper surface, and yellowish-grey beneath; the ears are nearly concealed in the fur; and the incisor teeth are deep yellow in front, and very strong, presenting a considerable resemblance to those of the Beaver, to which great Rodent the Voles were formerly considered to be related. It is very widely distributed, being found in all parts of Europe, and stretching right across Central and Northern Asia, to China, the Amoor region, and the Sea of Okhotsk. In Ireland, however, it is not found. Its habits vary a little in different localities, but in general it haunts the banks of rivers, in which it burrows to a considerable distance. In the water it is very active, swimming and diving with the greatest facility, and it is here that it seeks its food, which appears to consist exclusively of vegetable substances. Professor Bell says:—“A decided preference is shown, during the summer months, for the inner or concealed part of some species of sword-flags, which is very succulent and sweet-tasted. As this portion is usually below water, the animal gnaws the plant in two near its root, when it rises to the surface, and being conveyed to some sound footing, is consumed at leisure. In default of its more favourite food, it will make a satisfactory meal on the common duckweed. Only the green and fleshy leaf is eaten, the roots and other fibrous parts being rejected. While feeding on this plant, the creature sits like a Squirrel on its haunches near the water’s edge, and taking up a lump of the soft and slimy-looking mass in its fore paws, eats a small part only, and letting the remainder fall, takes up some more in the same manner.” The accusation sometimes brought against the Water Vole of eating worms and insects, and even of destroying fish-spawn, young fishes, and even young ducks, seems to be entirely unfounded. In the winter the Water Voles will feed on turnips, mangel-wurzel, and other roots, and also upon the bark of osiers and willows, to which they do considerable damage; and in some localities they appear to frequent gardens at all seasons of the year, burrowing in the ground, and feeding luxuriously upon the produce of the gardener’s labour. Their greatest activity is in the twilight, but in quiet situations they are to be seen abroad during the day. The female produces from two to six young at a litter: twice in the year in Britain, according to Professor Bell; three or four times in the course of the summer, according to Brehm and other Continental naturalists.

MOLAR TEETH OF THE WATER RAT.

A second British species is the FIELD VOLE, or Short-tailed Field Mouse (Arvicola agrestis), which is less than half the size of the Water Vole, and has the tail only about one-third the length of the body, instead of half that length. In the general form of the head and body the two species are a good deal alike, but the ears project farther beyond the fur in the Field Vole. The general colour of this species is greyish-brown, becoming tinged with reddish or yellowish on the sides; the lower surface is pale grey or dirty white, and the tail is brown above and greyish beneath. The Field Vole is a very abundant species in the northern and central parts of Europe, but is wanting in Ireland and south of the Alps and Pyrenees. It is usually found in damp places, especially in meadows in the neighbourhood of woods and copses, where it forms burrows of considerable extent. Its food consists almost exclusively of vegetable substances, such as roots and herbage, and in times of scarcity it will climb up trees and bushes to feed on the tender parts of the bark. In case of necessity, however, it does not disdain animal food, but will eat insects and meat, and even sometimes kill and devour smaller individuals of its own species. It breeds three or four times in the year, producing from four to six young at a birth, in a small round nest made of moss and leaves, among the roots of the herbage in some hollow of the ground. Their increase, which would otherwise be very formidable, is checked by the smaller predaceous beasts and birds, such as the Weasel, the Kestrel, and the Owls, which destroy them in great numbers. The BANK VOLE (Arvicola glareolus[53]), the third British species, which is chestnut-coloured, with white feet and with a longish tail, closely resembles the preceding species in its habits, but feeds rather on fruits and roots than on herbage, and is far more addicted to a diet of animal food, freely devouring insects, worms, snails, and even young birds and carrion. It is pretty generally distributed over Europe, but not so uniformly as the Field Vole, which it even exceeds in fecundity, the females producing from four to eight young three or four times in the year, in a nest constructed of grass and moss placed in a hollow of the surface of the ground among dense herbage.

SOUTHERN FIELD VOLE.

The Continent of Europe is inhabited by several other species of Voles, among which we may notice the little SOUTHERN FIELD VOLE (Arvicola arvalis), which more or less completely takes the place of our common Field Vole in Southern Europe, but also extends over the whole of Central Europe, and into Western Asia. Several of these species, and others to which we cannot specially refer, ascend to considerable elevations on the mountain-sides, but at least one species, the SNOW MOUSE (Arvicola nivalis), lives on the Alps and Pyrenees, at elevations of 4,000 feet and upwards, being most abundant about the limit of perpetual snow, where it not only resides during the short period of summer, when some portion of the surface is freed from its snowy covering, but actually throughout the winter, buried under the snow, through which it makes its way in search of the roots of plants. The ROOT VOLE (Arvicola oeconomus) is a large and abundant Siberian species, the range of which extends from the Obi to Kamstchatka. This and some other northern species often migrate in great bodies, after the fashion to which we shall have to refer when speaking of the Lemmings.

In North America, it would appear from Dr. Coues’ monograph, there are about a dozen distinct species of Voles. One of them, confined to the northern parts of the Continent, he identifies with the Arvicola rutilus of the Old World, which he regards as a circumpolar species. South of a line running from sea to sea, a little north of the boundary of the United States, comes another form, A. Gapperi, which is regarded as a sub-species of A. rutilus, to which A. glareolus (see p. 116) is considered to stand in a similar relation. The most abundant North American species is the MEADOW MOUSE (A. riparius), which is distributed, apparently, over the greater part of the Continent, and takes the place of the Field Vole. On the prairies there is a peculiar species (A. austerus), a sub-species of which (A. curtatus) is found in the Western territories as far as California; the PINE MOUSE (A. pinetorum) inhabits the country east of the Mississippi; and the genus is represented in Mexico by one species (A. quasiater). The Voles are most numerous and abundant in the northern and north-western parts of North America.

Another American species is the MUSQUASH, MUSK-RAT, or ONDATRA (Fiber zibethicus), which constitutes a genus distinguished from the true Voles by having the tail compressed and nearly naked, the hinder toes united by short webs, and fringed with long hairs, and the enamel folds of the molars united by a line running down the middle of the tooth. The form of the animal is thickset, and in this respect, as in its aquatic habits, it resembles the Beaver, to which it was formerly supposed to be nearly allied. The head is short and broad, the ears project very little beyond the fur, the hind limbs are longer than the fore legs, and terminate in five toes with strong claws, while the fore limbs have only four toes and a wart-like thumb; the fur is very thick and shiny, and the colour is usually brown above and grey below, with the tail, which is nearly as long as the body, black. The fur is well known in commerce. The length of the head and body of a full-grown male is about twelve inches. The name Musk-rat, often given to this species, refers to the musky odour diffused by the secretion of a large gland situated in the inguinal region.

The Musquash, which may be described as a large Water Rat, inhabits all the suitable parts of North America, from the thirteenth to the sixty-ninth degree of north latitude, and is most abundant in the Canadian region, which offers it peculiarly favourable conditions of life in the multitude of rivers and lakes, upon the banks of which the Musquash always takes up its abode. It is a nocturnal animal, passing the day in concealment, and coming forth with the twilight to seek its nourishment, and amuse itself with its fellows. In the water it displays wonderful activity, and, in many respects, presents much resemblance to the Beaver. Curiously enough, the parallelism of habits holds good to a certain extent, even in the construction of their dwellings. The Musquash generally lives in a burrow dug out of the bank of the stream in which he disports himself, and consisting of a chamber with numerous passages, all of which open under the surface of the water. But, under certain conditions, especially in the north, he builds himself a house of a rounded or dome-like form, composed of sedges, grasses, and similar materials, plastered together with mud, and supported upon a mound of mud of sufficient height to raise it above the water. The house contains a single chamber from sixteen inches to two feet in diameter, and is entered by a passage which opens at the bottom of the water. Other passages are said to issue from this, and to lead down into the ground under the bottom of the water; these are made by the animal in his search for the roots of water-lilies and other aquatic plants, which constitute a great part of his nourishment. The Musquash also seeks provisions on land, and in this way often does much mischief in gardens. Fresh-water mussels also form a part of its diet. It passes the winter in its house, which it then furnishes with a soft bed of leaves, grasses, and sedges, and, according to Audubon, ventilates by covering the middle of the dome only with a layer of similar materials, through which the air can pass. Of the propagation of the Musquash very little seems to be known with certainty. They pair in April and May, and the female produces from three to six young at a birth; but whether this takes place once or several times in the course of the summer is a matter of doubt. They are captured in fall-traps baited with apples, or by traps set at the mouth of their burrows. The Indians sometimes spear them in their houses.

MUSQUASH.

The LEMMING (Myodes lemmus) is one of the most remarkable of the MuridÆ, on account of the great migrations which it performs, apparently with no special object. In Norway, where it is best known, they make their appearance in the cultivated districts in such enormous numbers, and so suddenly, that the peasants have always believed them to fall from the clouds. The Lemming is a Vole-like animal, about six inches long, of which the tail makes up about half an inch. It varies considerably in colour, but is usually brownish-yellow, with dark spots above, and with a yellow streak enclosing the eye on each side of the face; the under surface is yellowish. The ears are very short, scarcely projecting beyond the fur; the eyes are small, black, and bead-like; the soles of the feet are hairy, and the claws of the fore feet much stronger than those on the hinder extremities. The Norwegian Lemmings live and breed among the peat mosses of the mountains. They are lively and active little creatures both by day and night, and feed upon the scanty vegetation of their Alpine home—grasses, lichens, the catkins of the dwarf birch, and roots. They are active even through the winter, when they make passages for themselves under the thick covering of snow which then veils the whole country, and thus are enabled to go in search of their ordinary food. They also make their way up to the surface, upon which they may occasionally be seen running, even in the depth of winter. They breed in their burrows and under stones, and must be very prolific, seeing that every predaceous animal in the country destroys and devours them. The Lemming is, in one sense, an exceedingly timid little creature, the slightest disturbance of its quietude, or even the passing over-head of a cloud, being sufficient to alarm it; but when attacked it displays the most dauntless courage, standing on the defensive against both men and animals, and biting very sharply at anything that comes within its reach. From time to time, from some unexplained cause, the Lemmings start in vast swarms from their mountain fastnesses, and make their way in a straight line in some definite direction. Nothing seems to turn them from their course; they go straight on, over hill and dale, and, although said at other times to have an aversion to water, they now swim across any lakes or rivers that come in their way. In this operation many of them lose their lives, for they require smooth water for their navigation, and the least breeze ruffling the surface suffices to send hundreds of them to the bottom. In this way they gradually arrive at the cultivated regions, where they do so much damage to vegetation, that in olden times a special form of prayer and exorcism was in use against them. Their march is accompanied by great numbers of carnivorous beasts and birds of all sorts. Wolves, Foxes, and Wild Cats, and the smaller quadrupeds of the family MustelidÆ, Eagles, Hawks, and Owls, all prey upon them with avidity—even the Reindeer is said to stamp them to death; and the story of his eating them, long discredited, has been confirmed on good authority, while man, with his Dogs and Cats, is not behindhand in the work of destruction. Nevertheless, a great multitude survives all these dangers, and, strange to say, the termination of this painful migration is always the sea, into which the survivors of the march plunge, and, apparently, voluntarily commit suicide. Mr. Crotch, who has published several papers on the Lemming and its migrations, says that in Norway these animals always proceed from the central backbone of the country in an east or west direction, and that in either case the survivors of the march drown themselves, those that go westward in the Atlantic, those that go eastward in the Gulf of Bothnia. His notion is that the migration is in obedience to an inherited instinct acquired at a time when there was land where the sea now rolls; but there are many difficulties in the way of such a hypothesis.

LEMMING.

Besides the Scandinavian Lemming above noticed, several other species occur in the northern parts of the world. Three species (Myodes lagurus, obensis, and torquatus) inhabit Siberia; the latter two are found in North America, the last also in Greenland. In this species, which has been placed in a distinct genus under the name of Cuniculus torquatus, the third and fourth toes of the fore feet are much larger than the second and fifth (the thumb being rudimentary), and their claws become periodically enlarged to double their ordinary size by an enormous growth during winter of horny matter on the lower surface.

The transition from this to the next family is effected by two genera, which to such an extent combine the characters of the two as to have led different zoologists to place them sometimes in the one, sometimes in the other. Externally they have all the characters of the Mole-rats of the following family; in the characters of the skull and teeth they more resemble the Voles. The ZOKOR (Siphneus aspalax), which may be taken as an example of these forms, is an inhabitant of the Altai Mountains, has the eyes very small, the external ears reduced to mere rudiments, the body cylindrical, as in the true Mole-rats, and the fore-feet armed with very long and strong claws, of which that on the fifth toe is longer than the toe itself. This animal lives in subterranean runs something like those of the Mole, but of much greater extent, and in burrowing in the earth makes use of its strong incisors to cut through the roots it meets with, and when necessary to loosen the earth. The runs pass very near the surface, and are no doubt made for the purpose of feeding on the tender roots of grasses. A species of Siphneus is said to occur in North China. The other genus (Ellobius) includes two species; one (E. luteus) from the country about the Sea of Aral; the other (E. talpinus) from south-eastern Russia and the west of Asia. The latter abounds in the Crimea. These animals form the sub-family SiphneinÆ.

SPALACIDÆ, OR MOLE RATS—Characteristics of the Family—Habits—Food—THE MOLE RAT—Distribution—Description—THE CHESTNUT MOLE RAT—THE NAKED MOLE RAT—THE STRAND MOLE RAT—Description—Habits—THE CAPE MOLE RAT—GEOMYIDÆ, OR POUCHED RATS—Characteristics of the Family—The Cheek-pouches—THE COMMON POCKET GOPHER—Distribution—Description—Burrowing—Runs—Subterranean Dwelling—THE NORTHERN POCKET GOPHER—HETEROMYINÆ, OR POUCHED MICE—Difficulties as to Position—Characteristics—PHILLIPS’ POCKET MOUSE—Where Found—Description—THE YELLOW POCKET MOUSE—THE LEAST POCKET MOUSE—DIPODIDÆ, OR JERBOAS—Organisation for Jumping—Characteristics—Distribution—THE AMERICAN JUMPING MOUSE—Description—Characters peculiar to itself—Habits—THE TRUE JERBOAS—Characters—THE JERBOA—Distribution—Habits—Mode of Locomotion—THE ALACTAGA—THE CAPE JUMPING HARE—THE PORCUPINE-LIKE RODENTS—OCTODONTIDÆ—Characteristics—Sub-Family CTENODACTYLINÆ—THE GUNDI—THE DEGU—Description—Habits—THE BROWN SCHIZODON—THE TUKOTUKO—THE CURURO—THE ROCK RAT—Sub-Family, ECHINOMYINÆ—THE COYPU—One of the Largest Rodents—Description—Burrows—Habits—Mother and Young—THE HUTIA CONGA—THE HUTIA CARABALI—THE GROUND RAT.

FAMILY VIII.—SPALACIDÆ (MOLE RATS).

ALTHOUGH the Zokor and its allies in the preceding family have to a certain extent prepared us for the peculiar characters presented by the Mole-rats, these are exhibited by the latter in a much more extreme form. They have a very large broad head, which is usually flattened above, and forms an appropriate anterior termination to a clumsy, cylindrical body, supported upon short stout limbs; their incisor teeth are large and broad, and are most formidably exposed in front of the mouth; their eyes are exceedingly small, hidden in the fur, and sometimes quite rudimentary; the external ears are reduced to the smallest possible size, or altogether wanting; and their tails are either so short as to be concealed within the hair of the hinder part of the body, or altogether wanting externally, although the skeleton still shows some caudal vertebrÆ. The molar teeth are rooted, and not tuberculate; their surface shows re-entering folds of enamel. The feet have five toes, but the thumb is generally very small, although furnished with a nail. The number of molars varies from three to six on each side in each jaw.

In their mode of life, as in their form and the condition of the organs of sight and hearing, these animals present a considerable resemblance to the Moles; but as their food is exclusively of a vegetable nature, the object of their burrowing is not exactly the same. They all inhabit the eastern hemisphere, and are generally met with in dry sandy plains, the soil of which lends itself readily to mining operations. They seldom quit their burrows, and usually work in these only at night, when they make their way rapidly through the ground, and, like the Mole, can run either backwards or forwards in their subterranean galleries with equal facility. They feed chiefly on roots, and especially on the bulbs and tubers which so many plants possess in the dry districts which they frequent; but some of them also eat nuts, seeds, the young bark of trees, and herbage. None of them fall into a state of torpidity during the winter—indeed, only two species inhabit northern regions; but these, although active in the winter season, are said not to take the precaution to lay up a store of provisions.

SKULL OF MOLE-RAT.

Most zoologists distinguish two groups of SpalacidÆ. In the SPALACINÆ, the representatives of which range from south-eastern Europe to further India and the south of China, and also occur in Africa in the countries of Abyssinia and Shoa, the palate between the molar teeth is broader than one of the sockets of the molars, and the angular portion of the lower jaw springs from the lower edge of the bony case of the incisor. To this group belongs the MOLE-RAT (Spalax typhlus), which inhabits Hungary and Galicia, and the south-east of Europe generally, and ranges eastwards into Asia as far as the Caucasus and Ekaterinoslav. It possesses only three molars on each side in each jaw, and has the eyes rudimentary and covered by the skin, so that the animal is quite blind; the upper incisors are placed perpendicularly; and the tail reduced to a sort of wart. The toes, especially those of the fore-feet, are furnished with very powerful claws, which are vigorously employed by the animal in the digging operations above described. The general covering of the body is a soft fur of a yellowish-brown colour, tinged with ashy-grey; the head lighter, but becoming brownish behind; and the lower surface ashy-grey, with some white streaks and spots. The muzzle, chin, and feet are whitish, and along each side of the face there runs a sort of ridge of stiff bristle-like hairs. This species is particularly abundant in the Ukraine and the country about the Volga and the Don.

The genus Rhizomys, of which there are an East Indian and two African species known, has the eyes uncovered, though very small, short naked ears, and a short partially hairy tail. The upper incisors are arched forward. The CHESTNUT MOLE-RAT (Rhizomys badius) lives in Northern India, Siam, and Arracan; and, according to Mr. Finlayson, the food of a specimen in confinement consisted of unhusked rice and other grain, but he showed himself fond of yams and pumpkins. The NAKED MOLE-RAT (Heterocephalus glaber), which has no external ears and a short tail, has the body almost entirely naked. It is a native of Shoa.

MOLE-RAT.

The other section of the Mole rat family, the BATHYERGINÆ, is entirely confined to Africa, and, indeed, almost exclusively to the southern extremity of that continent, only a single species being found elsewhere—at Mozambique. They show a resemblance to the Hystricine Rodents in the structure of the lower jaw, the angular portion of which springs from the side of the bony case of the lower incisor; and the palate between the molars is narrower than in the SpalacinÆ. The best known of the six species inhabiting the Cape of Good Hope is the STRAND MOLE-RAT (Bathyergus maritimus), which is nearly as large as a small Rabbit, its length being about ten inches, with a tail two inches in length. In general form it resembles the species last described; it has small but uncovered eyes, a broad nose, no external ears; very long, compressed, and powerful claws on all the toes, except the thumb of the fore-feet, which has a crooked nail; four molars on each side, and long white incisors, of which the upper ones are strongly grooved in front. The colour of the fur is greyish-white, with a yellowish tint on the upper surface. The tail has a sort of radiating tuft of hairs at the end. The Strand Mole-rat lives entirely in sandy localities near the sea-shore, and especially in the sand-hills or dunes which fringe the coast of the Cape of Good Hope in some parts. Here it burrows freely in all directions, its galleries generally radiating from several central points, and joining in various places. It avoids the light as much as possible, and if by chance it is exposed on the surface it is exceedingly helpless. Very little is known of the habits of this species, which probably feeds chiefly on roots like the other members of the family. It is regarded as mischievous, as it undermines the ground so much as to make it unsafe to ride over. The colonists, therefore, often destroy it by various means. The enamel folds of the teeth become effaced with use.

The Georychi, five species of which inhabit Cape Colony, resemble the preceding species, but are smaller and weaker. The claws of the fore-feet are shorter and weaker, and the upper incisors, which are long and arched forward, are not grooved. The best-known species is the so-called CAPE MOLE-RAT (Georychus capensis). In the Mozambique species (Heliophobius argenteo-cinereus) there are six molars on each side above and below, and the second toe of the hind feet is the longest. In most other characters it resembles Georychus.

FAMILY IX.—GEOMYIDÆ, OR POUCHED RATS.

The Pouched Rats, or Pocket Gophers, and the Pouched Mice of North America, constitute a family distinguished from all the preceding forms by the presence of a pair of great cheek-pouches, opening outside and not inside the mouth (see figure). These cheek-pouches are hairy inside throughout. The angular portion of the lower jaw is strongly twisted, the molars are four in number on each side in each jaw, and the squamosal bone is very large. In external characters the animals of this family present considerable diversity, which has led to their being divided into two well-marked sub-families, the distinctive peculiarities of which are of such importance that Dr. Coues has raised them to the rank of distinct families. The GEOMYINÆ, or Pouched Rats, are more or less Rat-like animals, in which the feet are five-toed, and all the toes furnished with claws, those of the fore feet being very strongly developed; and the tail is short. Certain other characters are presented by the skull. The outline of this part, including the zygomatic arches, is almost quadrangular; the infra-orbital opening is far in front of the jugal process; the malar bone extends forward to the lachrymal.

MOLAR TEETH OF THE MEXICAN POUCHED RAT.

UNDER SURFACE OF THE HEAD OF HETEROMYS.

Of the animals thus characterised, the Continent of North America possesses, according to Dr. Coues, seven species, and they are met with from Hudson’s Bay and the Columbia River in the north, as far south as Mexico. The best-known species, the COMMON POCKET GOPHER (Geomys bursarius), inhabits the whole valley of the Mississippi, and extends northwards into Canada. It reaches the foot of the Rocky Mountains in Colorado, but is not known to occur west of that range. It is also found in Texas. This Pouched Rat, like the rest of its genus, has the incisors broad and the upper ones deeply grooved; but in addition to the ordinary deep groove it has a fine line close to the inner margin of each of these teeth. Its form is stout and clumsy, but its coat is beautifully soft and velvety, like that of the Mole, but of a dull reddish-brown colour, with the feet and tail white. The average length of an adult specimen is from seven to eight inches, and the tail is two or three inches long. This organ is clothed with hair nearly to the tip.

SKULL OF THE MEXICAN POUCHED RAT.

Like the Mole, this animal lives in burrows, which it makes in all directions in the ground, throwing out as it proceeds heaps of earth, which exactly resemble ordinary mole-hills. To enable it to perform these labours the claws of the fore feet are exceedingly powerful; and to adapt it the better to its subterranean existence, the eyes are very small, and the external ears are wanting. Its digging operations have generally the same object as those of the Mole—namely, the search for food. The tunnel is carried along not far from the surface of the ground, and the roots of any plants that lie in its course are bitten off and devoured by the little miner. Besides the runs, the Pouched Rat digs himself a convenient dwelling in the shape of a chamber hollowed out under the roots of a tree, access to which is gained by a somewhat spiral descending passage. This chamber, which is usually at a depth of four or five feet, is comfortably lined with soft grass, and the nest in which the female brings forth her young is a cavity of the same kind, but surrounded by circular passages, from which, like that of the Mole, other passages branch off. One of these, according to Gesner, leads from the nest to a large store-chamber filled with nuts, seeds, and roots, among which the potato was found to play an important part. These provisions are carried to the store-house in the great cheek-pouches, which the animal is said to fill by the aid of its tongue, and to empty with the fore paws. This Pouched Rat does much damage in cultivated ground by attacking the roots of both plants and trees, sometimes destroying a great number of the latter in a few days. The female produces from five to seven young at the end of March or the beginning of April. The other species of Geomys closely resemble this in their habits.

Of the second genus belonging to this sub-family (Thomomys) Dr. Coues admits only two species, one of which, however, occurs under three named forms. They may be distinguished from the species of Geomys by their having the upper incisors plain, without grooves.

The NORTHERN POCKET GOPHER (Thomomys talpoides), with its sub-species, ranges over nearly the whole of North America from the Hudson’s Bay Territory to California and New Mexico. The three forms are for the most part in accordance with geographical distribution. A small species (Thomomys clusius) has been obtained in the Rocky Mountains.

The HETEROMYINÆ (forming the family SaccomyidÆ of Dr. Coues, although he does not accept the genus Saccomys) are more slender and delicate in form than the GeomyinÆ, and have the hind limbs and tail elongated, the former, indeed, being converted into leaping organs like those of the Jerboas and Kangaroos. The eyes and ears are larger, and the animals are in every respect adapted to life in the open, while the GeomyinÆ, on the contrary, are subterranean in their habits. The hair in the present family is coarse and harsh, sometimes even spiny. In skeletal characters we find a similar alteration. The incisors are narrow; the skull is delicate, with its angles rounded off, and the mastoid bones form a considerable part of the roof of the cranial cavity; the zygomatic arches are slender; and, the lower root of the maxillary process being undeveloped, the infra-orbital opening is not defined. As in the Jerboas, the cervical vertebrÆ are sometimes anchylosed. Like the GeomyinÆ, these animals are confined to America, and chiefly limited to the Southern United States and Central America, although some of the species occur as far north as the Columbia River and Hudson’s Bay, and one is found in Trinidad. By American writers they are called “Pocket Mice.”

PHILLIPS’S POCKET MOUSE, also known as the Kangaroo Rat (Dipodomys Phillipsii), is one of the best known species of this group. It is an elegantly formed little creature, about four inches long, with a slender tail nearly six inches in length. Its colour above is mouse-brown, white beneath; the sides of the body have some white streaks, especially one from the ear towards the shoulder, and one on the thigh running towards the root of the tail; the tip of the tail is also white. This is a Californian species, but extends throughout the Pacific region of the United States. It is represented in the Rocky Mountains by a rather larger and stouter form, with smaller ears and a shorter tail (Dipodomys Ordii), which is generally regarded as distinct, but is placed by Dr. Coues as a sub-species. The habits of the species are comparatively little known, but they appear to live in the most desert places they can find, the barren spots on which the only plants that seem to flourish are the great mis-shapen cactuses. They dwell in holes under rocks and stones, from which they emerge at sunset, and hop about gaily after the fashion of little Kangaroos. The places in which these Pocket Mice are found are so bare of vegetation and destitute of water, that it is difficult to imagine how they contrive to exist. In all probability they pick up a scanty living in the shape of roots and grasses, especially seeds, carrying a supply for the day into their holes in their great cheek-pouches.

The YELLOW POCKET MOUSE and the LEAST POCKET MOUSE (Cricetodipus flavus and parvus) are very minute creatures, only about two inches long in the head and body. The tail is longer than the head and body in the latter, shorter in the former species, and the colour of the fur in both is a pale buff. These species are found in the Rocky Mountains and the region west of that range to the Pacific, the latter being inhabited by the second of the above species. Several species of the genus Heteromys inhabit Central America, and one is found in the island of Trinidad. Nothing appears to be known of their habits.

From these we pass as by a natural transition to

FAMILY X.—DIPODIDÆ (THE JERBOAS).

The JERBOAS are a more extensive and much more widely distributed family of hopping Rodents. In these we find the organisation for jumping brought to greater perfection than in any other group. The body is light and slender, the hind limbs much elongated, the fore limbs very small, and the tail long and usually tufted at the end. The number of toes on the hind feet varies from three to five, and the metatarsal bones are very often united so as to form what is called a “cannon bone” in the Horse. The incisor teeth are compressed; the molars sometimes four, but usually three in each series, rooted or rootless, not tuberculate; the infra-orbital opening is rounded and very large, and the zygomatic arch slender. The great home of these animals is the vast steppe region which stretches from South-eastern Europe across the greater part of Central Asia, but they extend southwards round the eastern extremity of the Mediterranean, through Syria and Arabia to Egypt and Africa, over a great part of which they are found, and eastward to India, Afghanistan, and Ceylon. A single species occurs at the Cape of Good Hope; and another is found in North America. We may commence by noticing this last species, as it not only makes the nearest approach to those of preceding families, especially the MuridÆ, but differs from the rest of the Jerboas in characters of such importance, that Dr. Coues maintains its right to form a separate family (ZapodidÆ).

SKULL OF THE CAPE JUMPING HARE.

The AMERICAN JUMPING MOUSE (Zapus[54] hudsonius) has a wide range, extending across the continent of North America from sea to sea, and from Labrador, Hudson’s Bay, and the Great Slave Lake in the north, to Virginia and the elevated portions of Arizona and New Mexico in the south. It is an elegant little mouse-like creature, rather more than three inches long, and furnished with a cylindrical tail, which exceeds the head and body in length by about two inches. Its hind limbs are not quite so disproportionately developed as in the other members of the family. Its fur in summer is of a brown colour above, becoming yellowish on the sides and white below; in the winter the brown tint covers the whole surface. The ears, which are not very large, are black, with a light-coloured rim; the hind feet are greyish, and the fore feet whitish on the upper surface; and the tail, which tapers to an exceedingly fine point, where there is a fine pencil of hairs, is ringed and nearly naked.

The characters in which this animal differs from its nearest relatives are as follows:—In the upper jaw there are four rooted molars on each side, the first being very small, the second the largest, and the rest gradually diminishing in size; the fore feet have the thumbs rudimentary, and the hind feet have five toes, all of which touch the ground; the metatarsal bones are separate; and the soles of the feet naked, with granules and small horny shields.

AMERICAN JUMPING MOUSE.

The American Jumping Mouse is found in meadows in the neighbourhood of woods and copses. It is nocturnal in its activity, sleeping during the day in its burrow, which is usually about two feet deep, and coming forth at night. It is sociable in its habits, and excessively active, covering from three to five feet of ground at each leap, so that it is a matter of no little difficulty to capture a specimen in the open. In the woods it is worse, as the little creature will bound over bushes, and get out of sight in a moment. Its food consists of seeds of various kinds, and it is exceedingly fond of beech-mast. For protection from the cold of winter the Jumping Mouse makes a little hollow clay ball, within which it coils itself up, and goes comfortably to sleep. The nest is made about six inches under the surface of the ground, and is composed of fine grass, sometimes mixed with feathers, wool, and hair; and in this the female produces from two to four young, probably several times in the course of the summer, as the nests and young are to be found from May to August.

MOLAR TEETH OF THE JERBOA.

If we regard the American Jumping Mouse as constituting a peculiar section of the family, ZAPODINÆ, a second group, DIPODINÆ, is formed by the TRUE JERBOAS, which make up the greater part of the family. These either possess only three molars, or a very small additional tooth exists in front of each series in the upper jaw. The molars are rooted, and diminish in size backwards in each series. The cervical vertebrÆ are anchylosed; the fore feet have the thumbs rudimentary, but sometimes furnished with a small nail; the hind feet have only three toes fully developed, and the metatarsals are united into a single bone of great length; the soles are furnished with elastic balls; and the tail is very long, well-clothed with hair, and tufted at the end.

JERBOA.

Of these pretty little creatures, which are in some respects singularly bird-like, about twenty species have been recorded, and these occupy the whole of the Old World area of the family, except South Africa. The JERBOA (Dipus Ægyptius) may serve as an example of this section of the family. This is a most lively and active little creature, which inhabits the deserts of north-eastern Africa as far south as Nubia, and extends its range into Arabia and south-western Asia. On these arid plains, so scantily clothed with a few grasses and dry shrubs that it is difficult to conceive how any animal can find a living on them, the Jerboa lives, often in numerous societies, and in company with the few birds and lizards which enliven the wilderness. These animals dwell in subterranean abodes consisting of many branched galleries, which they dig out in the hard soil not far from the surface. The Arabs assert that these habitations are produced by the joint labour of the whole society. They retreat into their burrows at the least alarm. The females are said to produce from two to four young at a birth in a nest made in the deeper part of the burrow, and lined with hair pulled from the under surface of her own body. When going along quietly, the Jerboa walks and runs by alternate steps of the hind feet, but when there is occasion for rapid motion it springs from both feet at the same time, covering so much ground at each leap, and touching the ground so momentarily between them, that its motion is more like that of a bird skimming close to the surface of the ground than that of a four-footed beast.

The Jerboa is about six inches long, with a tail about eight inches in length exclusive of the tuft with which its tip is adorned. Its upper surface is of a greyish sand-colour, like that of many other desert animals; the lower surface is white; and the tail pale-yellowish above and white beneath, with the tuft white, with an arrow-shaped black mark on its upper surface.

ALACTAGA.

Several other species of Jerboas are known, some from the deserts of North Africa, others from the steppes of Central Asia. The latter region harbours some forms, which differ from the preceding, among other characters, by having five toes in the hind feet, whereas the true Jerboas have only three, but of the five toes only three are sufficiently developed to take part in the animal’s progression. The best known of them is the ALACTAGA (Alactaga jaculus), a rather larger species than the Jerboa, and with a still longer tail, reddish-yellow with a greyish tinge above, white beneath and on the hind legs. Its range extends from the Crimea and the steppes of the Don across Central Asia to the borders of China. It walks upon all-fours, and when advancing quickly springs along after the fashion of the Jerboa. Its food consists of all sorts of vegetable substances, but it is especially fond of the bulbs of plants, and does not refuse occasionally to eat insects, or even the eggs and young of the birds which inhabit the steppes with it. The Alactagas live in very complicated burrows, with many passages and branches, and they are said always to make one passage from the central chamber of their residence, which terminates close to the surface of the earth at some distance, but is only opened in case of danger, when the inhabitants escape through it, the position of its intended aperture being previously unrecognisable. In cold weather they sleep in their nests. The female produces from five or six to eight young, in a nest lined with her own hair. Species of Alactaga occur not only in Central Asia, but also in Arabia and North Africa.

MOLAR TEETH OF THE JUMPING HARE.

South Africa produces one species, the CAPE JUMPING HARE (Pedetes caffer), which constitutes a distinct sub-family, PEDETINÆ, having four rootless molars on each side in each jaw, the metatarsal bones separate, the tail bushy, and the hind feet furnished with four toes having broad, hoof-like nails. This is a much larger animal than any of the preceding, being about the size of the common Hare, which it also resembles in its colours. The Jumping Hare inhabits a considerable portion of South Africa, extending on the west coast at least as far as Angola. It is abundant at the Cape of Good Hope, both in the mountains and in the plains. Great numbers of the animals often live together, and their burrows, which, like those of other DipodidÆ, are inhabited by numerous individuals as a common residence, consist of many-branched galleries made at no great depth from the surface, but leading into a more deeply-seated habitation. They generally go about slowly upon all-fours, but can advance with extraordinary rapidity by Kangaroo-like springs, in each of which, when pressed, they will cover a space of twenty or thirty feet. Their food consists of roots, seeds, and herbage. The female produces three or four young at a birth.

CAPE JUMPING HARE.

SECTION III.—PORCUPINE-LIKE RODENTS (HYSTRICOMORPHA).

FAMILY XI.—OCTODONTIDÆ.

This first family of the Porcupine alliance consists of a number of rat-like animals, nearly all of which are inhabitants of South America, three species only being peculiar to the large West Indian Islands, whilst, singularly enough, four more are known from different parts of the African continent. Except in one of these last, all the members of the family have four molars on each side in each jaw, and the crowns of these teeth show internal and external folds of enamel. The malar portion of the zygomatic arch has an angular process at its lower margin. The hind limbs are not disproportionately developed, and both they and the fore feet are nearly always furnished with five toes, armed with curved claws; and the clavicles are perfect. The ears are generally short and sparingly hairy, and the tail, which is of various lengths, is either clad with short hairs, or naked and scaly.

We may begin with two African species of this generally American family, which have the two inner claws of the hind feet furnished with comb-like fringes of horny bristles, whence the name of Ctenodactylus has been applied to the best known species. These two species, which exhibit strong affinities to the Jerboas, form the sub-family CTENODACTYLINÆ. The GUNDI (Ctenodactylus Massoni) has only three molars on each side in each jaw, and only four toes upon each foot. It is an animal about the size of the Water Rat, but with a mere stump of a tail, very small ears, very long whiskers, and the hind limbs rather longer than their fellows. It lives in North Africa, chiefly on the borders of the Sahara, where it takes up its abode in the rocky hills, and descends therefrom to the cultivated grounds to feast upon the growing corn. It is diurnal in its habits, but exceedingly shy and watchful, making off to its fastnesses at the least appearance of danger. Pectinator Spekei, a species named after its discoverer, the celebrated African traveller, is nearly related to the preceding, but has a small additional molar in each series. The tail is of moderate length, and bushy, and the ears have a small antitragus. It inhabits the Somali land in the interior of North-eastern Africa.

The DEGU (Octodon Cumingii), a very abundant species in Chili, which also extends into Peru, may be taken as a typical example of the whole family, and also of its typical sub-family OCTODONTINÆ, in which the molars are simply indented on each side. The fur is soft, and the tail is short. The Degu is a rat-like animal, rather smaller than the Water Vole, the head and body measuring from seven and a half to eight inches in length, and the tail, exclusive of its terminal tuft, rather more than half that length. The general colour of the animal is brownish-yellow, pencilled with black on the back; the lower surface is yellowish, the feet white, and the tail dusky above, whitish beneath, with the tufted tip dusky or blackish. In the central parts of Chili, according to various travellers, the Degu is exceedingly abundant, living in large societies about hedges and thickets, and running about boldly, even on the high roads. The animals make their burrows in the hedge-banks and similar places, and when alarmed rush into them with their tails elevated, very much after the manner of Rabbits. As the burrows communicate freely with each other, the Degus can easily escape pursuit, going in at one opening and coming out at another at some considerable distance. They sometimes climb up into the bushes among which they live. Their ordinary food consists of the herbage which grows about their dwelling-places, but they also invade gardens and fields, where they may do considerable damage. In the winter they will feed upon the tender bark of certain trees, but they are said by some authors to lay up a store of food against this season. They do not become torpid. The female is believed to produce two broods in the year, each consisting of from four to six young. Two other species of Octodon are known from Chili and Bolivia, which region is also inhabited by two species of Habrocoma, a genus distinguished by the large size of the ears, and the extreme softness of the fur. In these animals the molar teeth differ in the two jaws, the upper ones being as simple as in the preceding species, while the lower ones show a complication of the enamel folds like what we shall meet with in the third sub-family.

The BROWN SCHIZODON (Schizodon fuscus), which inhabits certain elevated spots in the southern part of the Andes (75° S. lat.), has the enamel folds of the molar teeth meeting in the middle. It is about the size of the common Rat (seven and a half to nine inches long), and has a shortish tail clothed throughout with short hairs. Its fur is dark brown above, dirty yellowish beneath. This animal inhabits grassy places near mountain streams, where the ground is sometimes so undermined by its burrows as to render travelling on horseback very uncomfortable. It is a nocturnal animal, and passes most of its life underground. The valleys it inhabits are covered with snow for at least four months in the year.

In the TUKOTUKO (Ctenomys brasiliensis) and its congeners, about four of which are known from different parts of South America, one of them extending as far south as the Strait of Magellan, the eyes and ears are very small, and the animal seems to be still more specially adapted to a subterranean mode of life. In these animals the claws are longer than the toes, and those of the hind feet are fringed with a sort of comb formed of bristles. The incisor teeth are very broad. The Tukotuko is about the size of a large Rat, namely, from eight and a half to nine and a half inches long, with the tail from two and a half to three and a half inches. Its name is in imitation of the sound which it constantly emits—a sound which rather surprises a stranger when he first hears it, seeing that the animal uttering it is concealed underground. In many places, as in the Argentine Republic, this animal is exceedingly numerous, living generally in sandy soil, but sometimes in damp situations. It makes long burrows not far from the surface, and thus in some places completely undermines the ground. In making these galleries the Tukotuko is engaged in the search for its food, which consists chiefly of the roots of plants. According to Azara, it lays up stores of food in its burrows. Its activity is nocturnal.

The CURURO (Spalacopus PÖppigii) has the ears quite rudimentary, and is also organised for a subterranean existence. This and another species inhabit Chili, where they make extensive burrows in the ground, and feed upon the bulbous and tuberous roots of various plants, large stores of which they collect in their subterranean abodes. These magazines are sought out by the poorer people, and their contents used as food.

The ROCK RAT (Petromys typicus), although most nearly allied to the preceding species, lives on the opposite side of the Atlantic in the rocky hills of South Africa, especially towards the mouth of the Orange River. It differs from the preceding forms in the harshness of its fur, in which it resembles another sub-family of OctodontidÆ, in the shortness of its thumbs, which are furnished with a small nail, and in its rather bushy tail. The molars are semi-rooted, with the enamel folds nearly meeting in the middle. The whiskers are of great length, and entirely black. The general colour is reddish-brown, with the head and fore parts greyish, the throat whitish, and the belly pale yellow. The tail is of the colour of the body at the root, with the remainder black. The length of the animal is about seven and a half inches, of the tail from five to five and a half inches. It feeds upon various vegetable substances, and appears to be very fond of the flowers of syngenesious plants, especially a species of groundsel, which it eagerly devours. It forms its retreat among loose stones, or in crevices of the rocks.

While the OctodontinÆ may be regarded as specially characteristic of the region of the Andes, the other great group of this family is almost exclusively confined to the country east of that great chain, and to some of the West Indian islands. Curiously enough this sub-family also has a single representative in Africa. Its members are distinguished at once by the complicated enamel folds of their molar teeth in both jaws, by these teeth being generally rooted, and by the texture of the fur, which is harsh and frequently mixed with fine spines. Hence the name of Echinomys (Spiny, or rather Hedgehog, Rat), applied to the typical genus, from which the sub-family is named ECHINOMYINÆ. The tail in these animals is usually long.

The Rodents belonging to this sub-family are generally of considerable size, as large as Rats, or larger, stoutly built, with the hinder part of the body larger than the fore-quarters, with limbs of moderate length, the hinder larger than the anterior, the former furnished with five toes, the latter with four complete digits and a rudimentary thumb, and the toes armed with strong curved claws. The tail is scaly, with scattered hairs. In their habits these animals appear to be strictly vegetable-feeders, but in other respects they present some variety. The majority live in and upon the ground; but one or two are arboreal, and one aquatic, in their mode of life.

The last species alluded to is the well-known COYPU (Myopotamus Coypus), one of the largest of Rodents, which occurs in nearly all parts of South America and on both sides of the Andes, from the tropic of Capricorn to about 15° N. lat. It is usually about twenty inches long, but often attains still greater dimensions. The tail, which is about two-thirds the length of the head and body, is scaly, with hairs about as thickly scattered as in the common Rat. The ears are of moderate size; the incisor teeth very large and powerful; the molars, the hindmost of which are the largest, have two internal and two external enamel-folds in the upper, and three internal folds and one external in the lower, jaw; the hind feet are webbed. The general colour of the upper surface is brown, produced by dusky and brownish-yellow pencilling; the sides and under parts are brownish-yellow, and the front of the muzzle and the chin white.

The Coypus live upon the shores of the rivers and lakes of South America, generally, according to Rengger, in pairs, each pair digging for themselves a burrow in the bank, which extends to a depth of three or four feet, and widens out into a cavity eighteen inches or two feet in diameter. Here they pass the night, and take refuge when necessary during the day. They select for their dwelling-places the stiller parts of the water, where the aquatic plants on which they chiefly feed grow freely. They are said to swim well, but not to be expert in diving. On land they are slow and awkward in their movements. They feed chiefly on the roots of plants, but in the Chonos Archipelago, where the Coypus frequent the sea and make their burrows at some little distance from the beach, they are said occasionally to eat shell-fish. The female produces from four to five young once in the year. The little animals very early accompany their mother into the water, when she swims with them on her back, until they have acquired the art of swimming. Mr. Waterhouse thinks that this habit may “explain the singular position of the nipples noticed in the female Coypu. Of these four were found by Mr. Lereboullet on each side of the body, and situated rather above the mesial line of the flanks, the foremost being placed behind the shoulder, and the hindermost in front of the thigh.” The Coypu is hunted for the sake of its flesh, which is described as white and of good flavour, and of its skin, which is well known in the fur trade under the name of “Nutria,” signifying Otter. Great quantities of these skins are annually exported from Buenos Ayres. It is said to be a courageous animal, fighting bravely with the dogs engaged in chasing it.

The HUTIA CONGA (Capromys pilorides) is another large Rodent, measuring from twenty to twenty-two inches in length, with a stout rat-like tail about half as long as the head and body. It is an inhabitant of Cuba. The incisors are considerably smaller and weaker than in the Coypu; the upper molars have one internal and two external folds; the lower ones are similar but reversed. The fur, which is long, is very harsh, and consists of a mixture of black and yellow hairs, becoming rusty on the hinder part of the body. The belly is rusty yellow. This animal lives in the dense forests of Cuba, where it resides either upon the trees or in the thick underwood. It is a nocturnal or crepuscular animal, and is tolerably active when going about on the branches of trees, but is less at home on the ground. Its food consists of fruits, leaves, and the bark of trees, but, according to M. Ramon de la Sagra, it does not disdain animal food, and is especially fond of a species of Lizard belonging to the genus Anolis. On the other hand, the negroes are very partial to the flesh of the Hutia, and they capture the animal either by snaring it on the branches of trees, or by sending Dogs after it. Like the Coypu, it is said to fight courageously against its pursuers. Another Cuban species, the HUTIA CARABALI (C. prehensilis), has a slightly longer tail, which is prehensile at the tip. It is described as keeping chiefly to the highest branches of the trees. In St. Domingo there is an allied form, Plagiodon Ædium, in which the enamel folds of the molars are singularly complex (see figure on p. 132). This animal frequents the neighbourhood of human habitations, and approaches them at night in search of its food, which consists of fruit and roots. In most of the other members of this sub-family, which appear to be terrestrial in their habits, the intermixture of spines with the fur of the back is a striking character. In the genus Echinomys itself, and in Loncheres, which together include about a dozen species found chiefly in Guiana and Brazil, the spines frequently form the principal outer covering of the back. Side by side with these hedgehog-like species, however, others occur in which the fur is soft.

The GROUND RAT (Aulacodus Swinderianus), of Western and Southern Africa, is remarkable as being the sole representative of this group outside the South American province. It has very broad incisors, and those of the upper jaw exhibit three deep grooves; the molars show the same arrangement of folds as in Capromys; the fur is harsh and bristly, and of a general brown tint; and the tail is of moderate length, sparingly haired, dusky above, and whitish below. The fore feet have the thumb rudimentary and the outer toe very short; and the hind feet have only four toes, of which the outer one is rudimentary. This curious animal, which is nearly two feet long, is known to be an inhabitant of Sierra Leone and the Gambia, and also of South Africa (Port Natal); in all probability it occurs at many intermediate localities. In Sierra Leone it is known as the Ground Rat, or Ground Pig, and is said to feed upon ground nuts, and cassada and other roots in search of which it digs into the ground, where it also forms large burrows for its residence.

HYSTRICIDÆ, THE PORCUPINES—Conversion of Hairs into Spines—Skull—Dentition—Tail—Sub-families—The True Porcupines—The Tree Porcupines—THE COMMON PORCUPINE—Distribution—Description—The Crest of Bristles—Nature of the Spines—Habits—Young—Flesh—On the Defensive—Other Species—Species of Tree Porcupines—THE COUENDOU—THE COUIY—Description—Habits—THE URSON, OR CANADA PORCUPINE—Description—Habits—Food—CHINCHILLIDÆ, THE CHINCHILLAS—Characteristics—THE VISCACHA—Description—Life on the Pampas—Their Burrows—Habits—The Chinchillas of the Andes—THE CHINCHILLA—THE SHORT-TAILED CHINCHILLA—CUVIER’S CHINCHILLA—THE PALE-FOOTED CHINCHILLA—DASYPROCTIDÆ, THE AGOUTIS—Characters—THE AGOUTI—Distribution—Appearance—Habits—AZARA’S AGOUTI—THE ACOUCHY—THE PACA—Appearance—Distribution—Habits—DINOMYIDÆ—Founded for a Single Species—Description—Rarity—CAVIIDÆ, THE CAVIES—Characteristics—THE RESTLESS CAVY—Appearance—Habits—The Guinea-Pig Controversy—THE BOLIVIAN CAVY—THE ROCK CAVY—THE SOUTHERN CAVY—THE PATAGONIAN CAVY, OR MARA—Peculiar Features—Its Burrows—Mode of Running—THE CAPYBARA—Its Teeth—Where Found—Habits—THE DOUBLE-TOOTHED RODENTS—Characteristics—LEPORIDÆ, THE HARES AND RABBITS—Structural Peculiarities—Distribution—Disposition—THE COMMON HARE—Hind Legs—Speed—Its “Doubles”—Other Artifices—Its “Form”—Habits—Food—Pet Hares—THE RABBIT—Distribution—Habits—Domesticated—THE MOUNTAIN HARE—LAGOMYIDÆ, THE PIKAS—Characteristics—Distribution—THE ALPINE PIKA—THE ROCKY MOUNTAIN PIKA.

FAMILY XII.—HYSTRICIDÆ (PORCUPINES).

THIS second family of the section Hystricomorpha exhibits the conversion of the hairs into spines in perfection, the whole upper part of the body being in several instances completely covered with long, hollow, pointed quills, whilst in all cases great numbers of spines and stiff bristles are mixed with the hair. The form of the skull in these animals is distinctive. It is ovate, the cranial portion being more or less inflated by air-cavities in the bones, and the facial portion short, but the occipital or hinder surface is usually nearly perpendicular; the malar portion of the zygoma has no angular process as in the preceding family; the molar teeth are four in number on each side in each jaw; and the limbs are about equal in development. The incisor teeth are large and powerful. With regard to the development of the tail there are considerable differences, some species having that organ quite short, while in others it is of moderate length, or long and sometimes prehensile.

The Porcupines fall readily into two distinct groups (sub-families) characterised by structure, habits, and geographical distribution. In the strictly terrestrial species, or True Porcupines (HYSTRICINÆ), which inhabit the warmer parts of the eastern hemisphere, the skull is rather more elongated than in the others; the front margin of the orbit is over the third molar; the molars are rootless when young, but become closed after a time, and the clavicles are imperfect. The upper lip is furrowed; the tail, which may be either long or short, is never prehensile; the soles of the feet are smooth; and the female has six teats.

The arboreal species (SPHINGURINÆ), which are all American, have the skull peculiarly short, the front margin of the orbit over the first molar, the molars always rooted, and the clavicles perfect. The upper lip is not furrowed; the tail is moderate or long, and generally prehensile; the soles of the feet are covered with wart-like tubercles; and the female has only four teats.

The COMMON PORCUPINE (Hystrix cristata) may serve as a characteristic and well-known example of the first of these two groups. It is an inhabitant of the Mediterranean region, occurring in most parts of North Africa, and extending as far southwards as the Gambia and Soudan; in Southern Europe it is abundant in Italy, Sicily, and Greece. It measures about twenty-seven or twenty-eight inches in length to the root of the tail, which is about four inches long. The head, shoulders, limbs, and under parts are clothed with short spines intermixed with hairs usually of a dusky or brownish-black hue; the neck is marked with a whitish collar; from the back of the head and neck there rises a great crest of long bristles, many of them fifteen or sixteen inches in length, which can be elevated and depressed at the pleasure of the animal, are gently curved backwards, and are either dusky with the extremities white, or whitish throughout; the hinder portion of the body is entirely covered by a great number of long, sharp spines, ringed with black and white, but always having the extremities white. These spines vary considerably in size, some of them being very long (fifteen or sixteen inches), comparatively slender and flexible; others shorter (from six to twelve inches), but much stouter. They are all hollow, or filled only with a sort of spongy tissue, but from their structure are exceedingly resistant, and when the animal erects them, which he is able to do by contracting the muscles of the skin in which their roots are imbedded, they constitute a most formidable armature. They appear to be but loosely attached to the skin, and readily fall out, a circumstance which no doubt gave rise to the belief prevalent among the ancients (and many moderns) that the Porcupine was able to shoot his spines at an approaching enemy, or even to project them behind him at a pursuer when he was rushing away in search of a place of safety. The tail of the animal bears at its tip about twenty spines of very curious construction; they are about two inches long, hollow, open, and cut off square at the end, and about a quarter of an inch in diameter for the greater part of their length, but they are inserted into the skin by the extremity of a thin stalk half an inch long.

The Porcupine lives in holes among the rocks, or in a burrow, which he makes for himself in ordinary ground. In this retreat he passes the day in sleep, coming forth in the evening in search of food, which consists of herbage of various kinds, fruits, roots, and the bark and leaves of trees and bushes. He is slow in his movements, and does not even display much activity in burrowing. His habits are solitary except during the pairing season; and during the winter he passes most of his time in his habitation, without, however, falling into a torpid state. The pairing takes place early in the year, but varies in this respect according to the climate of the locality; and in the spring or early summer the female produces from two to four young, in a nest carefully lined with leaves, grasses, roots, and other vegetable substances. The young Porcupines are born with their eyes open, and their bodies are covered with short, soft spines, which are pressed closely to the body. These speedily harden and grow longer, and the young do not appear to remain very long with their mother. The flesh of the Porcupine, like that of most purely vegetable-feeding Rodents, is very good, and is eaten in the countries where the animal occurs. When pursued or irritated, he stands on the defensive, erects his formidable quills and crest, stamps on the ground with his hind feet after the manner of a Hare, jerks himself towards the object of his dread, as if to wound it with his spines, and at the same time produces a curious noise by rattling the open quills of the tip of his tail. But all these manoeuvres are generally in vain, and the Porcupine, in spite of his defensive armour, is pretty easily captured by those who know how to set about it. The Leopard is said to manage the business at once by a single blow of his paw on the head.

A very similar Porcupine (Hystrix hirsutirostris) takes the place of this species in Syria and Asia Minor, and extends thence eastward to India; another (H. javanica) inhabits the Sunda Islands; and the district of Nepaul has a peculiar species of its own. In Siam and Malacca, and on the west coast of Africa, we find two species of an allied genus, in which the spines of the body are comparatively short and depressed, and the tail is elongated, scaly, with a few scattered bristles in the middle, and with a large tuft of long flat bristles at the tip. The Malayan species (Atherura fasciculata) is about eighteen inches long, the African one (A. africana) about fourteen inches. Both are somewhat rat-like in their form.

The Tree Porcupines, forming the second sub-family, several species with prehensile tails, range over the continent of South America, east of the Andes, and one of them, the Mexican Tree Porcupine (Sphingurus mexicanus), is found as far north as Guatemala and Southern Mexico. The most abundant and widely-distributed species in the Brazilian region are the COUENDOU (Sphingurus prehensilis) and the COUIY (S. villosus), inhabiting Guiana, Brazil, and Bolivia, the latter being found throughout the forest region of Brazil and as far south as Paraguay.

These animals are of considerable size, usually measuring from sixteen to twenty inches in length without the tail, which is about one-third the length of the head and body. By the aid of the prehensile tip of this organ they climb with great facility and security upon the branches of the trees, but their feet are also specially adapted for this particular mode of activity, and they are said even to climb the palm-trees in order to feed upon their fruit. They are nocturnal in their habits, passing the day in sleep concealed in the fork of a branch, and going abroad at night in search of their food, which consists of fruits of various kinds, and the buds, leaves, and even flowers, of the trees on which they live. Roots also form a part of their nourishment, probably when they reside rather among thickets than in the high forest. Their spines, although short when compared with those of the Common Porcupine, are formidable defensive weapons when the animal erects them; in some species, as especially in the Couiy, they are concealed, when depressed, by the long hair, and, according to Hensel, this serves as a protection to the animal from rapacious birds, for, when it sits in a heap, sleeping away the daylight, these soft grey hairs give it a most deceptive resemblance to a mass of the beard-moss which so commonly grows on the trees in the Brazilian forests.

The URSON, or CANADA PORCUPINE (Erythizon dorsatus), the only North American species of the family, according to Mr. Allen, although other writers distinguish two or three such forms, is about two feet or more in length when full grown, and is covered with woolly hair, and with long coarse hair of a dark brown colour, with the points white or yellowish, this difference in the colour of the tips of the hairs being the chief distinction between the two varieties which Mr. Allen recognises. The spines in both forms are white, with the points usually dusky or brown. The Canada Porcupine is distributed through the whole of the Eastern United States, except on the seaboard, from New York to Virginia, and north of the States through Canada, as far as the limit of trees. The Western Porcupine, which has the tips of the long hairs yellowish (whence it has received the name E. epixanthus), occurs west of the Missouri river, extending to the Pacific shores and going southward along the mountains to Arizona and New Mexico, and northwards at least as far as Alaska and Sitka.

Although a heavy and clumsy-looking beast, and destitute of the prehensile tail of its South American cousins, this Porcupine is a good climber, and passes nearly the whole of its life upon trees; nevertheless, according to Mr. Allen, it may be met with travelling upon the prairies, probably on its way from one suitable residence to another. On the ground it moves slowly, but its armature of spines is a protection against most of its enemies, and it has the art of striking very forcible and judicious blows with its spiny tail. Audubon and Bachmann mention many cases in which Dogs, Wolves, and even a Puma were found dead or dying in consequence of the severe inflammation caused by the spines of this animal sticking about their mouths; and the former gives an interesting account of a lesson in urbanity given by a captive Urson to a Mastiff that attacked him. The food of the Urson consists of various vegetable substances, fruits, buds, and the young shoots and leaves of trees. In the winter it subsists chiefly upon the bark, which it strips off the upper branches of the trees, and when it has taken up its abode upon a tree it stays there until the suitable bark has been consumed. As it prefers young trees this operation is generally effected pretty quickly, and in this way it is estimated that a single Porcupine may destroy hundreds of trees in the course of a winter. The Urson resides in the holes of trees, and in such situations, or in crevices among the rocks, the female prepares her nest, in which she brings forth usually two, but occasionally three or four, young in April or May.

FAMILY XIII.—CHINCHILLIDÆ (THE CHINCHILLAS).

In the Chinchillas, which form a small family peculiar to South America, the incisor teeth are short; the molars are rootless, divided by continuous folds of enamel into transverse plates, and the two series in each jaw converge towards the front; the zygomatic arch has no angular process on the lower margin; the clavicles are slender but perfect; the fore limbs are small, the hind limbs long; the tail of moderate length or long, and turned up at the end; and the fur is very fine and soft. They are Rodents of moderate size and more or less of Rabbit-like appearance, except that the tail is always elongated and bushy. Of the five known species, four are inhabitants of the mountain regions, and one lives in the plains of the region of La Plata.

The latter, the VISCACHA (Lagostomus trichodactylus), is a stout-built and almost Marmot-like creature, from eighteen inches to two feet long, exclusive of the tail, which measures from six to eight inches. It has four toes on the fore limbs, and three on the hind feet, the latter furnished with long, compressed, and pointed nails; the muffle is broad and covered with a velvet-like coat of brown hair; the fur, which is soft and moderately long, is of a mottled grey colour above, and white or yellowish-white beneath; on each cheek there is a dark band; a white band crosses the muzzle and runs back on each side almost as far as the eye; the tail is dusky-brown or black.

The Viscacha lives on the Pampas from Buenos Ayres to the borders of Patagonia, and where it occurs is generally to be found in great numbers, residing in extensive burrows which it digs for itself in the ground, generally in the neighbourhood of copses, and, if possible, near cultivated fields. Each burrow has a great number of passages leading down to several chambers, in which the Viscachas live in family parties to the number of eight or ten. The Burrowing Owl already mentioned as an associate of the Prairie Dogs of North America, is found about the settlements of the Viscachas, living in their burrows, but it is said that the intrusion of these birds immediately drives out the real owners of the dwelling, as the Owls will not observe those rules of cleanliness which are characteristic of their unwilling hosts. Of course the expelled family has to make itself a new residence, and in this way great stretches of country come to be so undermined that they are dangerous to ride over. According to Mr. Darwin, the most favourite resort of the Viscachas in the neighbourhood of Buenos Ayres are those parts of the plain which, during half the year, are covered with great thistles.

They are nocturnal in their habits, passing the day sleeping in the recesses of their burrows, and coming forth in the twilight one by one, until a large and lively company is to be seen playing about the neighbourhood of their holes. When all is quiet they go in search of their food, which consists of grasses and other herbage and roots, and sometimes of the bark of trees and shrubs. In cultivated fields they may do considerable damage. While engaged in feeding, one or other of the party is perpetually on the watch, and the moment anything occurs to cause alarm, the whole of them scamper away with their tails elevated, to take refuge in their holes. In their movements they are very like Rabbits, but less active.

The Viscacha has the very singular habit of dragging all sorts of hard objects to the mouth of its burrow, where bones, stones, thistle-stalks, hard lumps of earth, dry cow-dung, and other chance articles may be found collected into a heap, frequently, according to Mr. Darwin, amounting to as much as a wheelbarrow would contain. Mr. Darwin says that he was informed that “a gentleman riding on a dark night dropped his watch; he returned in the morning, and by searching in the neighbourhood of every Viscacha hole on the line of road, as he expected, soon found it.” The purpose of this accumulation of apparently useless articles by the Viscacha has never been ascertained. It has been compared to the habit of some of the Australian Bower-birds, which adorn their playing-places with bright and glittering objects.

The Chinchillas of the Andes, or Alpine Chinchillas, are much lighter and more elegant animals than their cousins of the plains; in form they more resemble Squirrels or large Dormice. Their fur is excessively soft, perhaps the softest that clothes any animal, and in all the species it is of a grey colour, mottled or clouded with darker and lighter tints. The ears are of large size. They are confined to the Andes of Chili, Bolivia, and Peru, where they live among the bare rocks at a considerable elevation, seeking refuge in natural clefts and cavities, sleeping in their holes during the day, and coming forth at twilight in search of food. They are exceedingly lively and active in their movements, and very shy.

The COMMON CHINCHILLA (Chinchilla lanigera), the skins of which are well known as furs, is a squirrel-like animal, nine or ten inches long, with a tail more than half this length. It has large rounded ears; its fore feet have five, and its hind four, toes. Its fur on the upper part is grey, elegantly marbled with dusky or black, on the lower surface yellowish-white; the tail is black above, and dirty white at the sides and beneath. The incisors are of a bright orange colour in front. The SHORT-TAILED CHINCHILLA (C. brevicaudata), a larger species, has the tail only three inches long. Its fur is of a general silvery-grey hue, tinged with black, especially along the back, and the tail has two dark bands on its upper surface. Both these animals inhabit Peru, and the former is also found in Bolivia and Chili. They are exceedingly abundant, notwithstanding the constant persecution to which they are subjected for the sake of their skins. They come out of their holes even in the daytime, but then always keep on the shady side of the rocks. Their activity is described as wonderful, and they will run with great rapidity up perpendicular walls of rock which seem to offer no hold for their feet. On the ground they are said to run very much after the fashion of our common Mice. The Chinchilla seems to breed nearly all the year round, and the female is said to produce from four to six young at a birth.

The other two species of Alpine Chinchillas are placed in a separate genus, characterised by a more hare-like form, longer ears, and the presence of only four toes on both fore and hind feet. CUVIER’S CHINCHILLA (Lagidium Cuvieri) is about eighteen or twenty inches long, of an ashy-grey colour with a yellowish tinge above, and pale yellow beneath; the tail, which, with the hair, is nearly as long as the body is clothed beneath with short black hairs, and above with much longer bushy hairs, gradually increasing in length towards the tip, where they are black; a black line passes down the middle of the tail, and its sides are dirty white. The PALE-FOOTED CHINCHILLA (Lagidium pallipes), which is about the same size as the preceding, but has a shorter tail, is ashy grey, with a brownish tinge, becoming yellowish fawn colour beneath. The range of these animals seems to be the same as that of the true Chinchilla, but the second of them passes northwards into the mountains of Ecuador. In their habits they agree with the Chinchillas.

FAMILY XIV.—DASYPROCTIDÆ (AGOUTIS).

In the Agoutis we have the first of three more or less pig-like families, furnished with hoof-like nails on the toes, all the members of which are inhabitants of South America. The Agoutis especially may be compared to small slender-limbed Pigs, but they bear a still closer resemblance in external form to the little Musk Deer. The DasyproctidÆ have the incisors long; the molars, which are at first rootless, and afterwards close up, have enamel folds from both surfaces; the clavicles are rudimentary; the upper lip entire; the ears short; the tail short and naked, or quite rudimentary; and the fore feet have five toes.

Of these animals eight or nine species are known. They inhabit South America, from Mexico southwards to Paraguay and Bolivia, and some of them also occur in the larger West Indian Islands. They frequent the forest region, and especially haunt the banks of rivers.

The AGOUTI (Dasyprocta aguti), the most abundant and best-known species, is found chiefly in Guiana, Brazil, and eastern Peru, where it is to be found plentifully in the primeval forests. Like the other true Agoutis, it has only three toes on the hind foot; its ears are of moderate size and rounded; its form compact, and supported upon slender limbs; its tail rudimentary; and the hair of its back is coarse and harsh, and longer towards the hinder parts, which thus obtain a somewhat truncated appearance. Its general colour is olive brown, produced by a mixture of black and yellow; but the long hairs covering the hinder portion of the back are usually of an orange colour, and the middle line of the abdomen is whitish or yellow. This animal is from eighteen to twenty inches long.

Although inhabiting the forests, the Agouti is not unfrequently seen on the neighbouring grassy plains, but its residence is among the trees, in the hollows of which, or in cavities at their roots, it takes up its abode, generally lying concealed in its retreat during the day. It is very quick in its movements, runs well, and springs with almost the agility of an Antelope. The food of the Agouti consists of almost any vegetable substances that come in its way. It will eat grass and herbage, the roots of plants, their flowers and fruit, and when it lives in the neighbourhood of sugar plantations and gardens its inroads may give rise to considerable injury. The animal is, however, rather solitary in its habits, living by itself in its cell, in its departure from and return to which it appears generally to follow exactly the same roads, by which means a narrow but very distinct footpath is in course of time produced. This naturally often leads to the discovery and capture of the little recluse.

The Agouti appears to breed all the year round, usually producing two young ones at a birth. The female prepares her dwelling for the reception of her family by lining it comfortably with leaves, fine roots, and hair.

In the southern parts of Brazil, in Paraguay and Bolivia, the place of this species is taken by AZARA’S AGOUTI (Dasyprocta AzarÆ). A smaller species, the ACOUCHY (D. acouchy), is found not only in Guiana and the north of Brazil, but also in several of the West India Islands. The last-named species has a well-developed tail about two inches long.

Besides the Agoutis, this family includes an allied animal, the PACA (Coelogenys paca), which differs generically from the Agoutis by having five toes on the hind feet. It has a broader head and a blunter muzzle, and is altogether a rather stouter animal than the Agoutis; but, like most of them, it has a mere tubercle instead of a tail. One of the most remarkable characters presented by this animal, however, is the enormous development of the zygomatic arches, which are enlarged and inflated in the most extraordinary manner, the maxillary portion, which occupies the anterior two-thirds being hollowed out beneath into a great chamber, lined with mucous membrane, and opening into the mouth by a rather small aperture. The function of these remarkable cavities is at present quite unknown. Food is not to be found in them, and, indeed, as they are enclosed by solid bone, it would seem impossible that they could act as cheek-pouches.

The Paca, which inhabits Central and South America from Guatemala to Paraguay, is about two feet long, and is clothed with short rather coarse hair of a brown or yellowish-brown colour above, white beneath, with from three to five bands of white streaks and spots upon each side of the body. In its habits the Paca very much resembles the Agouti. It usually lives singly, or sometimes in pairs, on the borders of the forests, or near the banks of rivers, taking up its abode during the day either in a hole at the root of some tree, or in a burrow excavated by its own labour, which is generally carried to a depth of four or five feet. Its food consists of the leaves, fruits, and flowers of various plants, and, like the Agouti, it occasionally does mischief in the corn-fields and gardens. The female produces only one, or at most two, young at a birth. The Paca swims well, and can cross even a broad river in this way. Its flesh, like that of the Agouti, is very well flavoured, and is consumed both by natives and Europeans.

FAMILY XV.—DINOMYIDÆ.

This family has been founded for the reception of a single species, of which only a single specimen has hitherto been obtained. It is described by Professor Peters under the name of Dinomys Branickii. In its external appearance it closely resembles the Paca (Coelogenys paca), but may at once be distinguished from that animal by its possession of only four toes both before and behind. The ears are short and rounded; the upper lip deeply cleft; the incisors very broad; the molars four on each side, and divided into transverse plates by folds of enamel; the clavicles are imperfect; and the tail of moderate length and well clothed with hair. The animal, which inhabits the high mountain regions of Peru, is of the size of the Paca, or about two feet long, exclusive of the tail, which measures rather more than nine inches. Its general colour is grey, produced by the sprinkling of white among nearly black hairs; and on each side of the body are numerous large white spots, of which the upper ones nearly run together, so as to form two longitudinal bands. The extremity of the tail is black.

The only known example of this Rodent was obtained by M. Constantin Jelski at the Colonie Amable Maria, on the MontaÑa de Vitoc, in Peru, having been found at daybreak walking about the yard. It showed no fear of man, and was easily killed by a sword cut or two on the head. The species would appear to be rare, as the inhabitants of the neighbourhood were not acquainted with it. Of course nothing is known of its habits.

The chief interest at present attaching to this animal, therefore, consists in its peculiar combination of characters. Externally, as already stated, it resembles the Paca, with which it also agrees in the S-like form of the nostrils, and in the structure of the limbs (except the number of toes). In the lamellar structure of the molar teeth, in the structure of the skull, and of the skeleton generally, and especially in the flattened form of the front of the sternum and the development of clavicles, it differs from the Paca and all other Rodents with hoof-like nails. In some minor particulars it resembles the Capybara. By the structure of the molar teeth and certain osteological characters, it is most nearly allied to the Chinchillas; while it approaches the genus Capromys among the OctodontidÆ in the structure of the limbs and of some other parts of the skeleton. Professor Peters is evidently inclined to regard it as most nearly related to the ChinchillidÆ, but as constituting a group establishing a closer union than previously existed between the families ChinchillidÆ, OctodontidÆ, DasyproctidÆ, and CaviidÆ.

FAMILY XVI.—CAVIIDÆ (CAVIES).

This family, the last of the simple-toothed Rodents, includes a small number of species, of which the Common Guinea-pig may serve as a sort of type. The Guinea-pig is, however, one of the smaller species of the family, and is shorter in the limbs than most of its relatives. They have the incisor teeth short, that is to say, not extending far back in the jaw; the molars are rootless, variously divided by folds of enamel into lobes, the angles of which are acute; the palate is narrow in front, so that the upper series of molars approach each other rather closely in front; the clavicles are rudimentary or wanting; the fore limbs have four and the hind feet only three toes, all armed with hoof-like nails; the upper lip is not cleft; and the tail is rudimentary or wanting. They are stout, more or less rabbit-like animals, with a soft coat, and the ears variable in length; and they are confined to the continent of South America, where they chiefly inhabit the plains.

The RESTLESS CAVY (Cavia aperea), which is commonly regarded as the wild original of the so-called Guinea-pig (Cavia cobaya of some authors), is abundant on the banks of the Rio de la Plata, and extends thence northwards through Paraguay into Bolivia and Brazil. It is usually about nine inches long, with the fur of the upper part and sides of the body composed of a mixture of black and dingy yellow hairs, the chest greyish-brown, and the throat and belly pale dingy-yellow or brownish-grey. The incisor teeth are white. The genus to which this animal belongs may be at once distinguished from the other two genera constituting the family by the shortness of the limbs; the ears also are short; the feet are naked beneath; the hind toes are not webbed; and the molar teeth are nearly equal in size, and each composed of two angular lobes.

The specific name of the Restless Cavy seems to be derived from its popular name in the country where it occurs. According to Mr. Darwin, it is very common about the banks of the La Plata, sometimes frequenting sandy hillocks, and the hedge-rows formed of the agave and the prickly pear, but apparently preferring marshy places covered with aquatic plants. In dry places it makes a burrow; but when it frequents wet localities contents itself with the concealment afforded to it by the herbage. Rengger describes it also as generally haunting moist situations in Paraguay, and he adds that it keeps near the borders of forests, but is never found either in the forests or in the open fields. It lives in small societies of from six to fifteen individuals, in the impenetrable thickets of Bromelias, where its presence is revealed by the numerous beaten paths which it produces by going to and fro. In Bolivia, according to Mr. Bridges, it is peculiar to the low lands, and there takes shelter among the loose stones of the walls enclosing the fields. It is active in search of food early in the morning and in the evening, but will also come forth on gloomy days. Rengger and Azara both agree in the statement that the female produces only one or two young at a time; but the former says that this takes place only once in the year, whilst the latter describes the animal as breeding all the year round, and, indeed, in this way accounts for its abundance, notwithstanding its being preyed upon so extensively by rapacious birds and quadrupeds.

The question whether our common Guinea-pig is really the domesticated descendant of the animal just described can hardly be regarded as finally settled, and, indeed, independently of colour, there are sufficient differences between them to justify some doubt on the subject. The name Guinea-pig may, as Mr. Waterhouse suggests, be a mistake for Guiana-pig, and the first specimens may very probably have come from that part of America. Its prevalent colours, as is well known, are combinations of white, black, and yellow, and as these colours are shown in the drawings of Aldrovandus, dating back to within fifty years of the discovery of South America, there seems every reason to believe that the animal must have been long domesticated in America prior to its introduction into Europe. On the other hand, Dr. Rengger says that he saw fourteen Apereas representing the fifth or sixth generation from a single couple domesticated about seven years before, and that these exhibited no difference of colouring from the wild animal. Several allied species inhabit the great plains of South America.

The BOLIVIAN CAVY (Cavia boliviensis), which is grey in colour, with a faint yellowish tinge, with the throat and belly white, the feet whitish, and the incisor teeth orange yellow, inhabits the elevated parts of Bolivia, generally at a height of 10,000 or 12,000 feet. The ROCK CAVY (Cavia rupestris) is found in rocky districts in Brazil, where it shelters itself in holes and crevices. It is always found near the upper waters of rivers, and is a large species, measuring thirteen or fourteen inches in length. The SOUTHERN CAVY (Cavia australis), on the other hand, is a small species which inhabits Patagonia, where it ranges from 39° S. lat. to the Strait of Magellan.

This part of the world is also the abode of another and much larger species of the family, the PATAGONIAN CAVY or MARA (Dolichotis patachonica), an animal which somewhat resembles the Agouti in the length and comparative slenderness of its legs, and differs from all other Cavies in having tolerably long, pointed ears. It also possesses a very short tail. The molar teeth are rather small, and resemble those of the Guinea-pig in being formed of two nearly equal angular lobes, but the last molar in the upper jaw, and the first in the lower jaw, have three such lobes. The animal is somewhat Hare-like in its appearance, and has been mistaken for a Hare by superficial observers. It is, however, a much larger animal, measuring from thirty to thirty-six inches in length, and weighing from twenty to thirty-six pounds.

The Patagonian Cavy is clothed with a dense crisp fur of a grey colour on the upper part of the head and body, rusty yellow on the flanks, and white on the chin, throat, and belly; the rump is black, with a broad white band crossing it immediately above the tail. It inhabits Patagonia about as far south as 48°, and extends northwards into the La Plata territory as far as Mendoza. It is found only in the sterile desert part of the country, where the gravelly plains are thinly covered with a few stunted thorny bushes and a scanty herbage. The northern limit of the species, according to Mr. Darwin, is at the point where the vegetation of the plains becomes rather more luxuriant. The Patagonian Cavy usually burrows in the ground, but where it lives in the same region as the Viscacha, it will take advantage of the excavations made by that animal. It wanders to considerable distances from its home, and on these excursions two or three are usually seen together. Mr. Darwin says:—“It is a common feature in the landscape of Patagonia to see in the distance two or three of these Cavies hopping one after the other over the gravelly plains.” Their mode of running, on the same authority, more nearly resembles that of the Rabbit than of the Hare; though their limbs are long, they do not run very fast. They rarely squat like a Hare, but are very shy and watchful, and feed by day, in connection with which it is to be observed that the eyes are defended from the direct rays of the sun by well-developed eyelashes, which do not occur in the other Cavies. The female produces generally two young at a birth, which are brought forth and suckled in the burrow.

The CAPYBARA (Hydrochoerus capybara), the only other member of the present family, is the largest of all existing Rodents, large specimens measuring over four feet in length. It is a stout-built and massive animal, with limbs of moderate length, a large head with a very blunt muzzle, small eyes and ears, no tail, and both the fore and hind feet webbed. The upper incisor teeth have a broad and shallow groove down the front, and the molars present very remarkable characters. In the upper jaw the first three molars are each composed of two lobes united by cement, and on the outside of each of these lobes there is a fold of enamel which passes deeply into the tooth. The last molar consists of one lobe similar to those of the preceding teeth, but in place of the second there are ten or a dozen transverse plates. The first two molars of the lower jaw exhibit complex lobes and folds of enamel; the third and fourth a combination of folded lobes and transverse plates.

In its general form the Capybara is more pig-like than any of its relatives, and, indeed, its generic name, Hydrochoerus, Water-pig, recalls this resemblance, and at the same time intimates its aquatic habits. Its coat is composed of long and coarse hairs, often five or six inches long on the hinder parts, of a reddish-brown colour above, and a dirty brownish-yellow beneath. It is distributed over the whole eastern part of South America, from Guiana southwards to the Rio de la Plata, and ranges westwards into the lower parts of Peru and Bolivia.

The Capybaras frequent the borders of the lakes and rivers, with which all this part of the South American continent abounds, and, according to Mr. Darwin, they used to frequent the islands in the mouth of the La Plata, where the water is quite salt. In this part of America they are called “Carpinchos.” They never wander far from the water-side, and show a marked preference for the larger rivers, among the reeds and other plants fringing which they take up their abode. In populous districts they seem to pass the day in concealment, coming forth in search of food only at morning and evening, but where they are less in danger of pursuit they come out freely in the day-time. Seen from a little distance when walking they have much the appearance of Pigs, but they lose this when they sit, like the other Cavies, on their haunches. When danger threatens they emit a short, sharp bark, and immediately plunge into the water, where they swim about with little more than the nostrils above the surface; but under pressing circumstances they can dive and swim for a considerable distance under water. When swimming, the female is said to take her young ones on her back. About Maldonado Mr. Darwin observed that the Capybaras were usually to be seen only three or four together, but they are more numerous and go in larger companies more in the interior of the country. They constitute the ordinary food of the Jaguar, and are also eaten by the Indians, although their flesh is said not to be very good. The female produces five or six young at a birth, but has only one litter in the year. The young follow their mother about at a very early age.

With the Cavies concludes the long series of simple-toothed Rodents, and some of them, as we have seen, present no small resemblance to the Hares and Rabbits which constitute the greater part of the second great group into which we have divided the order. The chief peculiarity of this section, as has been already stated, consists in the presence in the upper jaw of a pair of minute incisor teeth, placed immediately behind the large effective incisors; and in the newly-born animal the number of these teeth is even greater, there being six incisors in the upper jaw, two of which fall out at an early period. Though the number of species included in this section is very considerable (about fifty, according to Mr. Wallace’s estimate), it includes only two families, and each of these contains only a single genus. We will commence with that which includes the best-known forms, the Hares and Rabbits.

FAMILY XVII.—LEPORIDÆ (HARES AND RABBITS).

The general appearance of these animals hardly needs to be described, and we may, therefore, indicate merely the structural peculiarities which serve to define the family. These consist in the presence of six rootless molars on each side in the upper, and five in the lower jaw (see figure on p. 82), each molar being divided into lobes by transverse folds of enamel; in the compressed form of the skull and the presence of wing-like post-orbital processes of the frontal bones; in the imperfect condition of the clavicles; the greater development of the hind limbs; and the presence of a short, bushy, upturned tail. The ears are long; the inner surface of the cheeks is more or less clothed with short hairs; the fore-limbs have five, and the hind-limbs only four toes; and the soles of the feet are hairy throughout. In all these characters, however they may differ in some respects, all the true Hares and Rabbits agree. The representatives of this family occur in nearly all parts of the world, but chiefly in the northern hemisphere, and the few species which pass down within the tropics are generally found only in mountainous regions. In the north they reach the Arctic regions in both continents. In the Old World a few species are scattered over India and Further India, and four or five occur in Africa, but chiefly in the southern part of the continent. In North America the species are numerous, and some of them range southward into Central America; but South America has only a single species, which occurs in the mountains of Brazil and upon the Andes.

As the whole of the family consists of animals to which in common parlance the names of Hares and Rabbits are given, we may take as examples of it the Hares and Rabbits which are so abundant in Great Britain, the other species agreeing generally with one or other of them in character and habits.

They may all be characterised as animals destitute of any means of defence against their enemies, except the rapidity of their movements, and as exceedingly shy and timid. Their general colour is a mixture of grey and brown, sometimes quite tawny, sometimes almost pure grey, and, as Mr. Bell remarks, “The admirable wisdom which has assigned such colours to a group of defenceless animals which conceal themselves amidst the brown sombre vegetation of woods and heaths, will appear more striking when it is recollected that certain species inhabiting the snowy regions of the north become wholly white in winter. All the members of the genus,” he adds, “are remarkable for their timidity, and their whole structure is such as at once to announce to them the presence of danger, and to enable them to escape from it. The eyes and ears are so formed and situate as to become instantly cognisant of even distant warnings of peril, and the limbs are admirably adapted for the most rapid flight.”

This last statement applies in a special manner to the COMMON HARE (Lepus europÆus), which is singularly well adapted for getting over the ground rapidly by the great length and powerful development of its hind legs. These organs are nearly twice as long as the fore limbs, and, as most of us are well aware, the bones composing them are set in motion by an enormous mass of solid muscle. Owing to their great preponderance the Hare, when moving slowly in search of food, goes with a sort of lolloping gait; but the moment there is occasion for him to move with rapidity, the disproportionate hind limbs stand him in good stead, and he shoots along over the ground by a series of long leaps, and with great swiftness. At the same time, it is observed that the length of its hind legs causes the Hare to run with much greater facility up hill than down, and, in fact, it is said that in descending steep inclines the animal is obliged to run obliquely in order to escape over-balancing itself. When pursued, the Hare has the art of making sudden turns in its course, known as “doubles” or “wrenches,” by which the Dogs in chase of it are thrown out, for although most Greyhounds are swifter of foot than a Hare, they are incapable of changing their course so sharply, and thus, while they are carried some distance onwards by their own impetus, their intended victim is making off in a different direction. They adopt other cunning artifices in order to escape from their pursuers, and some of these indicate a considerable amount of intelligence. Under such circumstances, and also in search of a more plentiful supply of food, the Hare will take to the water readily, and swim across rivers. Mr. Yarrell observed a Hare even swimming across an arm of the sea about a mile broad.

The Hare lives chiefly in cultivated fields, where it resides in a small depression of the surface, which is called its “form.” It shifts the situation of this simple residence according to the season, selecting a shady spot in summer, and a sunny one in winter, and going into cover in wet weather. It is rather a nocturnal or crepuscular than a day-feeding animal, although it may not unfrequently be seen abroad in the day. In the evening and early in the morning it is most active, passing the brighter hours at rest in its form. When out in the field in search of food it goes hopping along among the herbage and cultivated plants, every now and then sitting upright on its haunches and listening with erected ears for the slightest sound indicative of approaching danger. Its food is exclusively of a vegetable nature, but it seems to embrace pretty nearly the whole round of cultivated plants. Cruciferous plants appear to be amongst its favourite articles of diet, but it also does much damage to fields of young wheat. In the winter, when the open fields are covered with snow frozen hard, and, indeed, sometimes in the summer, the Hare will make his way into gardens in search of food, or, if this resource is not at hand, into plantations of young trees, where it will gnaw off and feed upon the bark, thus destroying great numbers of the trees. Mr. S. Mawson has recorded finding the stomach of a Hare killed in winter filled with hawthorn berries. After its wanderings the Hare always returns to its own form.

Hares pair when they are about a year old, and from that time produce several broods every year, each consisting of from two to five young, which are born covered with hair and with their eyes open. From Mr. Bell’s statement, these animals would appear to breed almost all the year round; he says that in mild winters young Hares have been found in January, and that he has known breeding continue till the middle of November. When captured young, the Hare may be easily tamed, and become an amusing pet, as, indeed, will be familiar to almost every one, through Cowper’s account of his Hares. Formerly the Hare used to be trained by jugglers to perform various tricks, one of which was the beating of a tambourine with its fore-feet, with which the animal will of its own accord drum upon the back of an offending companion. A relic of this practice is to be recognised in a common toy, which shows a small Hare sitting and beating a tambourine, its fore limbs being set in motion by the turning of the wheels of its stand.

The Common Hare is found spread over the greater part of Europe, from the south of Sweden and northern Russia to the Mediterranean and the Caucasus. It does not occur in Ireland. It varies somewhat in colour in different localities, and although it does not become white in winter, the northern forms show a tendency in that direction, and the others acquire a greyish tint at the approach of the cold weather.

THE RABBIT, or CONY (Lepus cuniculus), differs from the Hare in various characters; its colour is a tawny brownish-grey, the disproportion between the fore and hind limbs is not so great, and the ears are shorter, not exceeding the head in length. Although the Wild Rabbit is so plentiful in England as to become a pest to the farmers in many places, it is supposed not to be a native of north-western and central Europe, but to have been naturalised in Britain, its original home being in the countries bordering the Mediterranean. It is, and always was, very abundant in Spain, the name of which country (Hispania) has been supposed to mean the “country of Conies,” from the Phoenician and Hebrew word Schaphan, the name of the Hyrax or Cony of the Bible. Even in the present day it is very local in its distribution north of the Alps, and is not found at all in eastern and northern Europe. In Australia it has proved to be a veritable scourge.

In its habits the Rabbit differs from the Hare more than in its form and structure. Instead of contenting itself with a shallow depression as a resting-place on the surface of the ground, it digs deep holes in the ground, into which it may retire to sleep or at the approach of danger. It prefers light sandy soils for its residence, as these present great facilities for burrowing, and wherever particularly favourable conditions exist the Rabbits are to be found living together in very large societies. Furzy heaths are favourite places with them, as the ground is easily worked, and the furze bushes not only serve as a protection to the burrows, but furnish the Rabbit with an abundant supply of food, the young shoots being eaten off as high as the animals can reach when standing on their hind feet. In wet moors the Rabbits avoid burrowing, and live in runs and galleries formed in the matted heather and long herbage. Mr. Bell says that in more than one instance he has known a family to take possession of a hollow tree, ascending its inclined and decayed trunk for some distance.

Like the Hare, the Rabbit is generally quiet during the day, although it will not unfrequently be abroad at all hours. The evening, however, is its principal time for activity, and then the inhabitants of the warren may be seen playing about near their abodes, or wandering to greater distances in search of the green vegetables on which they feed. The moment there is the smallest suspicion of danger, the whole company scamper off at once to seek safety in their burrows. As they go, their white tails are the most conspicuous objects to be seen, and the spectacle of some hundreds of them rushing along at full speed, vanishing one after the other down the burrows, is lively and amusing enough.

The Rabbit begins breeding at six months old, and has several litters in each year. The young are usually from five to eight in number, sometimes even more; they are born blind and naked, and are produced in a separate burrow which the female digs for their reception, and lines with fur pulled from her own body. This brood-chamber has usually only a single entrance, and this the mother closes with earth after visiting and suckling her young family, which she is said to do only at night.

When domesticated, the Rabbit, as is well known, differs materially from its wild state. It is larger, and its colours are usually white, black, brown, or fawn colour, sometimes alone, sometimes mixed in patches. Albinoes are common, and form a permanent race. The Angora Rabbit, which is usually albino, has the hairs very long; and the so-called “fancy Rabbits” have the ears more or less pendent at the sides of the head, and often so long as to touch the ground.

A third British species is the MOUNTAIN HARE (Lepus variabilis), or Northern Hare, an inhabitant of all the northern parts of both hemispheres, which occurs in most parts of Scotland, and in Ireland, where, indeed, it takes the place of the common Hare. In its summer coat it is of a light fulvous grey colour, and is further distinguished from the common Hare by the shortness of the ears and tail, the former being shorter than the head, and the latter little more than half its length. In cold climates this animal becomes pure white in the winter. This Hare is absent from Central Europe, but reappears on the chain of the Alps.

It will be unnecessary to enter into details with regard to the other species of this family, all of which more or less resemble those just described, both in appearance and habits. They are distributed over nearly the whole world except the Australian region, but they are most numerous in North America, where a great many species have been described, which are reduced by Mr. Allen to twelve. Four of these, however, present well-marked local races, which double the number of recognised permanent forms.

FAMILY XVIII.—LAGOMYIDÆ (PIKAS).

In many respects the Pikas closely resemble the Hares, but they are distinguished by having only five molars on each side in each jaw, a depressed skull, with contracted frontal bones destitute of the wing-like process seen in the Hares, complete clavicles, short ears, limbs nearly equal in length, and no tail visible externally. They are much smaller than any of the LeporidÆ, the largest being no larger than a Guinea-pig, to which the animals have some resemblance; while in their habits they somewhat resemble the Marmots. When feeding they often produce a chirping or whistling noise, whence the name of Piping Hares, or Calling Hares, has been applied to them. Ten or a dozen supposed species of these animals have been described, most of them inhabiting the northern and mountainous parts of Asia, and one of these is also found in Europe, about the southern part of the Volga. In Asia species have been found as far south as the Himalayas and Nepaul. In North America a single species (Lagomys princeps) inhabits the Rocky Mountains, where it was first discovered by Sir John Richardson.

The ALPINE PIKA (Lagomys alpinus), which inhabits Siberia from the Irtish eastwards into Kamtchatka, is a little animal from nine to nine and a half inches long, of a greyish-brown colour above, yellowish-grey beneath; the feet are pale, and the ears dirty yellowish-white within, becoming dusky towards the margin, which is white. This animal occurs in considerable numbers in the Alpine and sub-Alpine parts of Siberia, where it either burrows in the ground, or shelters itself in crevices of rocks or among loose stones. The Pikas generally come out only at night, although they sometimes venture forth on a cloudy day. Their food consists of the scanty herbage to be found in their elevated abode, and as this would be impossible to procure during the winter when the ground is thickly covered with snow, the Pikas take care in the autumn to collect a large supply of dried grasses and other herbage, which they pile up near their habitations like little haystacks. They are, however, sometimes deprived of the fruits of their labour by the Sable-hunters, who plunder the Pikas’ stacks to feed their Horses. The female produces about six naked young early in the summer.

The ROCKY MOUNTAIN PIKA (Lagomys princeps) is a small species from six inches to seven and a half inches long, of a greyish-brown colour above, yellowish-brown on the sides, and greyish below. It received its specific name from its discoverer, Sir J. Richardson, in allusion to the name of “Little Chief Hare” given to it by the Indians. It inhabits the summits of the Rocky Mountains from Colorado northwards far within British America, and also occurs in the mountains of Utah, California, and Oregon. Mr. Allen describes its habits as follows:—“The animals are everywhere found in communities, living among the loose rocks from a little below timber-line nearly up to the snow-line. They appear to rarely wander many yards from their homes; are timid, yet easily become familiar. Though retreating to their homes when first alarmed, they soon come cautiously out one after another, till one may hear their sharp little cries in every direction. Their colour so nearly resembles that of the rocks they live among, that they are not easily seen, and their cry is of such a character as easily to mislead one in respect to the point from which it proceeds, seeming to be far away when only a few feet distant. They sit erect, like little Marmots.... They carry into fissures of the rocks large quantities of grass, which they lay up for winter consumption.”

CHAPTER V.
FOSSIL RODENTIA.

THE majority of the preceding families are more or less clearly represented by fossil remains, either in the younger strata of the earth’s crust, or in those cave-deposits of comparatively recent date which have furnished so many interesting relics of the Mammals of former days. It must be remarked, however, that while a considerable number of fossil Rodents have been named and described by palÆontologists, the materials upon which many of them have been established are very imperfect; in a great number of cases isolated molar or even incisor teeth furnish the sole evidence of the existence of creatures which were manifestly Rodents, but of which the other characters are rather difficult to divine from such scanty material. Still, imperfect as may be “the record of the rocks” in this as in other instances, it is in some parts sufficiently complete to enable us to trace back the existence of many forms of gnawing Mammals through a long period of geological time.

Of the SCIURIDÆ a considerable number of fossil species have been recorded. Species of the genera Sciurus, Arctomys, and Spermophilus, some of them identical with those still existing, have left their remains in Post-Tertiary deposits and in bone-caves in various parts of Europe; while species belonging to the first two genera, and to the American genus Tamias, have been detected in similar situations in North America. A few forms referred to the same genera go down still lower in the series of geological formations. True Squirrels are recorded from Miocene and Upper Eocene deposits in France, and a single species from the Tertiaries (probably Miocene) of Colorado; Marmots from Pliocene and Miocene beds in the South of France, and from a Pliocene deposit in Nebraska; and a Spermophile from the Miocene of Weisenau in Germany.

Besides these examples of known types, several fossils have been obtained both in Europe and America, which are regarded as indicating genera distinct from any now living. Plesiarctomys Gervaisii is founded on a fragment of jaw with four molars, obtained from Upper Eocene beds near Apt, Vaucluse. In its characters it appears to be intermediate between Squirrels and Marmots. Pseudosciurus suevicus, from the Upper Eocene (Bohnerz) of WÜrtemberg, seems to differ from all other SciuridÆ in the form of the molar teeth of the lower jaw, which are somewhat elongated, and have four tubercles arranged in two pairs, each pair being connected by a ridge. From the Tertiary deposits of the western territories of the United States, Professors Cope, Marsh, and Leidy have described several Sciurine Rodents as belonging to genera now extinct: thus Paramys has five species; Sciuravus (perhaps identical with the preceding), three; Heliscomys, Mysops, Colonymys, Taxymys, and Tillomys, one or two species each.

Of the ANOMALURIDÆ and HAPLODONTIDÆ no fossil remains are known. On the other hand, a North American fossil Rodent, described by Dr. Leidy under the name of Ischyromys typus, is regarded by Mr. Alston as the type of a distinct family, the IschyromyidÆ, nearly allied to the SciuridÆ, but also showing an affinity to the Beaver in some of its characters. The specimen described and figured by Dr. Leidy was obtained by Dr. Hayden from Miocene deposits in the “Bad Lands” of Wyoming. It was originally referred to the SciuridÆ, with which it agrees in its dentition, but is distinguished by its large infra-orbital opening, the presence of a sagittal crest, and the absence of post-orbital processes. The parietal region of the skull is much narrowed, and in this, as in the large size of the infra-orbital opening, Ischyromys resembles the Musk Rat.

Two other forms must be referred to here. Under the name of Pseudotomus hians, Professor Cope has described the remains of an animal which he believed to have been about the size of an Agouti, and originally thought to belong to the order Edentata. Subsequently he referred it to the SciuridÆ; but both Mr. Alston and Mr. Allen think that it may belong to the family IschyromyidÆ. In some respects the skull resembles that of Arctomys, but it has the same contraction between the orbits as Ischyromys and Fiber. The incisor teeth are separated, and Professor Cope believes that the animal had only three molars on each side in each jaw. A still more doubtful member of the family is Professor Cope’s genus Gymnoptychus, which includes four species, all said to be from the “Tertiary of the Plains.” In this genus there are five molars above and four below on each side, as in Ischyromys and the SciuridÆ; but these teeth show two crescents on the inner side in the upper, on the outer side in the lower jaw, and each crescent gives origin to a cross-ridge running to the opposite margin of the tooth.

The CASTORIDÆ, including at present only a single species common to the northern parts of both hemispheres, are represented by several peculiar fossil forms. Remains of the Common Beaver (Castor fiber) are not uncommon in peat bogs and other late superficial deposits both in Europe and America; and, according to Sir R. Owen, in association with those of the Rhinoceros, Mammoth, and Mastodon, even in the Fluvio-marine Crag (Newer Pliocene) of Norfolk. In Belgium its bones have been found in caves. Among the Mammals from the Upper Tertiaries of the Sivalik Hills, Messrs. Falconer and Cautley record a Beaver distinct from the existing species, although nearly allied to it. The skull of a great Beaver, one-fifth larger than that of the living species, was obtained many years ago by M. Fischer from sandy deposits on the shores of the Sea of Azov, and, as it differed in some peculiarities of the teeth from Castor fiber, was described by him as constituting a distinct genus under the name of Trogontherium Cuvieri. It is now regarded as a true Beaver, and named Castor Trogontherium. The British species, described and figured by Sir R. Owen from the Norfolk Forest bed under the name of Trogontherium Cuvieri, is, however, quite distinct, and belongs to the genus Diobroticus, characterised by having the third upper and first lower molar teeth with four enamel folds, and the rest only with two, most of the folds soon becoming isolated as the teeth wear down. This animal must have been nearly twice the size of the European Beaver.

At a still earlier period—namely, in the Miocene—the family CastoridÆ was represented, both in Europe and America, by some small species, nearly agreeing with the Beavers in dentition, but differing in the characters of certain bones of the skull. These form the genus Steneofiber. The largest (S. viciacensis), from the Miocene of the Allier, was about half the size of the Beaver; another (S. sansaniensis), from the fresh-water limestone of Sansan, was about as large as a Rat; an American species (S. nebrascensis), from the “Bad Lands” of Dakota, was rather smaller than a Marmot, and presented some resemblance to the Agoutis in the characters of the teeth; and a fourth species (S. pansus) occurs in the Santa FÉ marls. Eucastor tortus, a species rather smaller than a Marmot, is described by Dr. Leidy as very nearly related to the Beaver. Its remains were found in loose sands of the Niobrara River, Wyoming. Chalicomys and PalÆomys are genera doubtfully placed here. Their species occur in the Miocene and Pliocene of Europe.

Some bones of a gigantic Rodent, indicating an animal as large as a full-grown Black Bear, obtained from Quaternary and Alluvial deposits of various parts of the United States, have been described under the name of Castoroides ohioensis, Mr. J. W. Foster, its first describer, having an idea that it was a great Beaver. It has generally been known as the “Fossil Beaver” of North America, but several authors have entertained doubts of the correctness of this designation, and Mr. Allen has lately made it the type of a special family, CASTOROIDIDÆ, which he regards as most nearly related to the ChinchillidÆ. In the general aspect of the skull it resembles the Beaver, but in several details of structure approaches the Viscacha; while the structure of the molar teeth, which consist of a series of plates of dentine, completely enclosed by enamel, and held together by a thin coating of cement, occurs elsewhere only in the ChinchillidÆ, and in the last molar of the Capybara.

Dormice as well as Squirrels disported themselves in the Tertiary woods and thickets of Europe, and remains of several species of MYOXIDÆ occur in various deposits in France, Switzerland, and elsewhere, from the Upper Eocene onwards. Myoxus glis, the Garden Dormouse, has been identified with some doubt from the caves of Lunel Viel; and this is also probably the species occurring in the Belgian bone-caves, and described as Myoxus priscus by Dr. Schmerling. A species a little larger than the Dormouse occurs in Russian caves, and has received the name of Myoxus fossilis from M. Fischer; and the most striking species of all is also a Post-Pliocene form, namely, the gigantic Dormouse of Malta (M. melitensis). This animal, which seems to have been about the size of a Guinea-pig, must have been excessively abundant in Malta, for its describer, Professor Leith Adams, says that “its remains are met with in abundance throughout the cavern and fissure deposits, up even to the superficial alluvium now in course of formation.” From older times we have evidence of the existence of a Dormouse, about the size of the common species, at the time of the deposition of the gypsum of Montmartre (Upper Eocene), in which a well-preserved skeleton of the animal has been found. The same deposit has furnished traces of a second rather larger species. The Miocene of Switzerland and of Sansan has also yielded species of Myoxus; and Professor Hermann von Meyer has recorded a Dormouse from the Miocene of Weisenau, under the name of Brachymys ornatus.

No fossil LOPHIOMYIDÆ have yet been detected, but the great family MURIDÆ has left abundant evidence of its former existence. Species of the genera Mus, Arvicola, Myodes, and Cricetus, identical in many cases with those now living, have been obtained frequently in Post-Pliocene deposits and in bone-caves in Europe. Lemmings (Myodes lemmus and torquatus) are recorded from English caves. The genus Mus is also represented by several species in the Miocene deposits of France, and in the Sivalik beds investigated by Falconer and Cautley. The Miocene of Sansan has furnished a form which has been doubtfully regarded as a Gerbille, and named Meriones Laurillardi. In the same and other deposits of the same age in South-eastern France several species of an extinct genus (Cricetodon) have been obtained. Their dentition resembles that of the Hamster, but the first molars in both jaws have a tubercle less; the largest species (C. sansaniensis) rather exceeded the Hamster in size, while the smallest was less than a Mouse. Associated with some of these are two doubtful forms, Decticus and Elomys, the latter considered by M. Aymard, its describer, to be allied to Hydromys. The American fossil MuridÆ are for the most part either species of the genus Hesperomys, or nearly related to it. Twelve species of that genus were obtained by Dr. Lund from the Brazilian bone-caves, but of these eight were identified by him with species still existing. In North America two species of a nearly-allied genus (Eumys) have been obtained from Miocene deposits; and the bone-caves of Pennsylvania furnish the remains of a species of Neotoma (N. magister), hardly distinguishable from the Florida Rat.

A Rhizomys from the Sivalik deposits of North-western India is the only recorded fossil representative of the SPALACIDÆ; and of the GEOMYIDÆ the only known species are a Geomys from the Pliocene of Nebraska, nearly allied to, if not identical with, the living G. bursarius; and one from the “Tertiaries of the Plains,” described by Professor Cope as Colotaxis cristatus, which, however, has only three molars in the lower jaw.

The DIPODIDÆ are still more scantily represented. A Jerboa described by M. Fischer from Post-Pliocene deposits, probably of Tartary, is very nearly allied to the living Dipus platurus, but has shorter toes and broader cannon-bones. The genus DipoÏdes, from the “Bohnerz” of WÜrtemberg, is founded on a single tooth, and its position in this family is very doubtful.

On the other hand, some fossil allies of the DipodidÆ and GeomyidÆ constitute a distinct family, for which Mr. Alston proposed the name of THERIDOMYIDÆ, from that of one of its genera, Theridomys. In this genus, of which six species are recorded from the Eocene and Miocene deposits of France, there are four rooted molars in each series, and each of these has several enamel folds, some of which are converted into isolated loops as the crown is worn away. The best known species is Theridomys platiceps, from the Miocene of Caylus. In ArchÆomys chinchilloides there are still four molars, but these present a very different structure; they are rootless, and have the enamel folds extending diagonally across the crown, so that they are composed of a series of plates, thus presenting a certain amount of resemblance to the Chinchillas, which American family ArchÆomys was at one time supposed to represent in Europe. In fact, in the structure of their molar teeth, both the above genera approach American types; but in other characters, especially the form of the lower jaw, they appear to have been decidedly Mouse-like, and Mr. Alston regards them as most nearly related to the DipodidÆ, with which they are joined by a third form referred to the family Issiodoromys, a genus sometimes placed with the Jerboas. The teeth in this genus are of the same number as in the preceding, but the molars are much simpler, each of them exhibiting one large re-entering fold of enamel, which causes the surface of the tooth to present two heart-shaped lobes. This structure is not dissimilar to that prevailing in some DipodidÆ, and especially in Pedetes, but it was formerly thought to indicate a relationship to the Cavies, and accordingly the best-known species has received the name of Issiodoromys pseudanÆma (AnÆma being a sub-genus of Cavies). This species occurs abundantly in the Miocene lacustrine limestone near Issoire. A second species (I. minor) has been detected in the Upper Eocene of Lamandine-haute.

Of the OCTODONTIDÆ, an essentially American family at the present day, nearly all the recorded fossil forms are also American. Species of Echinomys, Loncheres, and Phyllomys were obtained by Dr. Lund from the Brazilian bone-caves, which also furnished him with the remains of a Coypu (Myopotamus antiquus), and of an allied form, Carterodon sulcidens, distinguished by its having broad incisors with longitudinal furrows and raised ridges. The latter has since been found living in South America. Another species, allied to Echinomys, is named by Lund Lonchophorus fossilis. The superficial deposits of South America have yielded the remains of two species of Ctenomys, one of which is believed to be identical with a recent species. As several species of this family now live in Africa, the occurrence in the eastern hemisphere of fossil forms belonging to it would not be surprising, but the few that have been referred to it are of very doubtful nature. M. Lartet obtained some isolated teeth from the Miocene of Sansan, which he described under the name of Myopotamus sansaniensis; and one or two other types (Aulacodon, Adelomys), from Upper Eocene and Miocene beds, are of very uncertain position.

Of the HYSTRICIDÆ, or Porcupines, remains have been obtained in both hemispheres. In the Old World traces of true Porcupines (Hystrix) are recorded from the Valley of the Arno, from the Sivaliks, the Pliocene deposits of the Auvergne, from Pikermi, and, on very doubtful evidence, from the Upper Eocene of Lamandine-basse; whilst Dr. Leidy has described two teeth from the Pliocene deposits of Dakota, as belonging to a species (Hystrix venustus) allied to the European Porcupine. This determination, if confirmed, would be of great interest, as no true Porcupine now occurs in America. Of the American type, two species of Sphingurus have been obtained from the Brazilian bone-caves; and Professor Cope records a species of the North American genus Erythizon from a similar cave in Pennsylvania.

The CHINCHILLIDÆ have left but scanty traces of their former existence. Lagostomus brasiliensis is from the Brazilian bone-caves; and Megamys patagoniensis from the Eocene sandstone of Patagonia. The latter species is founded upon a tibia and rotula, which on comparison seemed to approach most nearly to those of the Rodents of this family, and if the determination be correct it was probably one of the largest species of the order, as the tibia measures about a foot long. Amblyrhiza and Loxomylus, are two genera described by Professor Cope from bone-caves in Anguilla Island, West Indies.

The DASYPROCTIDÆ have but few fossil representatives, and the undoubted ones are all from the bone-caves of Brazil, which furnished Dr. Lund with two Agoutis and two Pacas. Of the former, one is described as Dasyprocta capreolus; the second is allied to the living D. caudata. The two species of Coelogenys are extinct. Some teeth, found in Tertiary deposits of the Puy-de-DÔme, have been referred to Dasyprocta, but this determination is excessively doubtful. Diobroticus schmerlingi from Belgian caves has been placed with the CastoridÆ.

Of the CAVIIDÆ, Dr. Lund obtained three species of the genus Cavia, and two of Hydrochoerus, from Brazilian bone-caves. Of the latter, one was allied to the existing Capybara; the other was a gigantic species, measuring about five feet in length. Dr. Leidy has described a species (Hydrochoerus Æsopi) from teeth found in Post-Pliocene deposits in South Carolina; and the Pampean deposits of the same age furnished M. D’Orbigny with the remains of a Cavy (Cavia antiqua) which, however, is doubtfully distinct from the Patagonian species.

The remains of species of the family LEPORIDÆ are very abundant in some Post-Pliocene cave deposits on both sides of the Atlantic, and in several cases the species are evidently identical with those now living. Besides these, species of the genus Lepus have been found in Pliocene and Miocene beds in France. In North America three extinct Leporine genera have been recognised, differing from Lepus in certain peculiarities of the molar teeth:—PalÆolagus, with three species, from the Miocene of Dakota and Colorado; Panolax, from the Pliocene marls of Santa FÉ; and Praotherium, from a bone-cave in Pennsylvania. The last-named genus has the crowns of the molars transversely oval, and without the enamel-band or crest which is seen on the surface of the teeth of other Hares.

The LAGOMYIDÆ are known in a fossil state chiefly from Post-Pliocene deposits, and the bone breccias of caves in various parts of Europe. In Post-Pliocene times the genus Lagomys seems to have been very generally distributed over the South of Europe; and the earliest appearance of the genus is in the Pliocene, three species having been described from deposits of that age at Œningen and Montpellier. The family is, however, carried further back in time by the genus Titanomys, in which the molars differ but slightly in structure from those of Lagomys, but there are only four of them in each series, both above and below. Two species of this genus have been recorded from Miocene deposits in France and Germany.

We have thus passed very briefly in review the fossil Rodents belonging to the two great sections of the order to which all its living species are to be referred; and it will be seen that while a knowledge of their existence is necessary to complete the history of the order, they present none of those peculiar characters which lend such interest to the fossil members of many other orders. There is, however, one fossil South American type to which we have yet to refer, as, by the curious combination of characters which it presents, it has long been somewhat of a puzzle to palÆontologists, and although generally placed among the Rodents, its peculiarities are such that Mr. Alston found himself compelled to establish a third primary section of the order for its reception. According to M. Bravard, the first discoverer of this peculiar type, the Pliocene deposits of the Pampas of La Plata contain the remains of three species belonging to it; but the bones which have been sent to Europe, and which represent most parts of the skeleton, seem all to belong to a single species, which has been very fully described by M. Serres under the name of Mesotherium cristatum.[55] What distinguishes it at once from all other known Rodents is the presence in the lower jaw of four incisor teeth, the second pair being very small and placed immediately behind the outer edge of the broad middle pair. The latter are peculiarly widened and compressed from front to back in both jaws, and their summits, instead of being worn to a sharp chisel-like edge as in ordinary Rodents, show an elongated ring of enamel surrounding a slightly depressed surface. Hence Mr. Alston denominated this section HEBETIDENTATA, or BLUNT-TOOTHED RODENTS. The enamel in all the incisors is continuous round the tooth. The molar teeth are rootless and curved, the convex side being directed outwards, contrary to what occurs in other Rodents. They are surrounded by enamel, and show re-entering folds which differ in the two jaws. Their number on each side is five in the upper and four in the lower jaw. The skull is massive, with enormously-developed sagittal and occipital crests, the latter of which run forward so far as to join the zygomatic arches; and these crests rise so high that the upper surface of the actual brain-case is entirely concealed by them when the skull is looked at from the side. The lower jaw in its characters presents some resemblance to the same part in the LeporidÆ; but it has the condyle for its articulation with the skull transverse, and fitting into a cavity of corresponding direction, a character which occurs in no other Rodent. Of the remainder of the skeleton we need only state that the animal possessed perfect clavicles; that the shoulder-blade and humerus somewhat resemble those of the Beaver; that the fibula articulated with the heel-bone; and that both front and hind limbs possessed five toes, some of which, judging from the form of the terminal joint, were probably furnished with hoof-like claws.

Thus, as regards its affinities in the order Rodentia, Mesotherium presents resemblances in its lower jaw (as also in some peculiarities of the skull), and in the articulation of the heel with the shank, to the Hares; while in the shortness of the incisors and some other cranial peculiarities, the form of the shoulder-blades, and the probably hoof-like character of the claws, we may notice an approach to the Cavies, which are also South American forms, and especially to the Capybara, which it probably resembled in its habits, although, if the evidence of the Beaver-like shoulder-blade and humerus be taken into account, it would appear to have been still more aquatic.

On the other hand, the resemblance to certain other Mammalia, and especially to some aberrant Ungulates, is unmistakable. The number of incisor teeth is the same as in Hyrax, and in these teeth there is also a certain amount of resemblance to the curious genus Toxodon, in which the incisors are four in the upper and six in the lower jaw, and worn away in somewhat the same fashion. In Toxodon also, the convexity of the curve of the molars is turned outwards. Certain other characters of Mesotherium—such as the mode of articulation of the lower jaw, and the peculiar connection of some of the caudal vertebrÆ with the ischiatic bones—present resemblances to the Edentata. As Mr. Alston says, “It appears to have been a survivor, to Pliocene times, of a much earlier type, which represented an era at which the Rodents were not yet clearly marked off from their allies. In fact, Mesotherium seems to continue into the order Glires that line of affinity which Professor Flower has pointed out as extending from the typical Ungulates through Hyracodon, Homalodontotherium, Nesodon, and Toxodon.”

The general relationships of Mesotherium to the other Rodents, and of these among themselves, are represented by Mr. Alston in a diagrammatic form, from which the following scheme, which will serve also as a table of the families, is derived:—

It seems quite clear, even from the above brief sketch of the history of the Rodentia in time, that, except in the case of Mesotherium, the fossil remains of animals belonging to this order furnish us with no important information bearing upon their alliances and possible origin. They make their earliest appearances, so far as we know, in deposits of Eocene age; and the earliest forms the remains of which are sufficient to give us a clear insight into their nature, are manifestly members of families, and often nearly allied to species still extant in the regions where their traces are now found. Thus in Eocene and Miocene deposits, we have representatives of the families SciuridÆ, CastoridÆ, MyoxidÆ, MuridÆ, GeomyidÆ, ChinchillidÆ, and LeporidÆ, already differentiated as at the present day, so far as the evidence goes; and it is clear that we must go much further back in time to seek the earliest appearance of the Rodent type, whether it branched off directly from the Marsupial series, or passed, as would seem to be indicated by Mesotherium, through a sequence of forms more or less related to the Ungulates.

Nor does the geographical distribution of the animals lead to any more definite conclusions. Certain families and even sub-families are of very wide range, the MuridÆ and SciuridÆ especially being represented nearly all over the world, while the HystricidÆ and LeporidÆ are also spread over very large areas, occurring in both hemispheres. Certain groups, such as the SciuridÆ of both sub-families, the CastoridÆ, the Murine, and Arvicoline sub-families of MuridÆ, the LeporidÆ, and the LagomyidÆ, may be said to have a circumpolar distribution in the northern hemisphere, nearly allied and sometimes identical species being found in the more northern parts of both the Old and the New World, but mixed with other forms peculiar to the regions, especially as we advance southwards. On the other hand, the MyoxidÆ are peculiar to the eastern hemisphere, as are also the SpalacidÆ and the DipodidÆ (with the exception of Zapus, which is considered by Dr. Coues to form a distinct family), and all the sub-families of MuridÆ, except those above mentioned as having a circumpolar range. The Myomorpha may in fact be looked upon as an Old World group, the GeomyidÆ being the only exclusively American family; while the Hystricomorpha as a whole may be regarded as American, certain aberrant forms of the OctodontidÆ inhabiting various parts of Africa and the Old World Porcupines being the sole representatives of that great section outside the western continent. Considering these facts, we may regard the Sciuromorpha and the Duplicidentata as originally polar types, or at all events as having an equal claim to an origin in the northern regions of either continent; while the Myomorpha, with their multitudinous forms spreading over all parts of the Old World, and having a much scantier representation in America, probably originated in the eastern hemisphere, and spread by a northern passage into the New World; and the Hystricomorpha would seem to have originated in South America, where they display the greatest variety of forms.

W. S. DALLAS.