Bats (Chiroptera).

With the exception of the great class of Birds, the Bats are the only surviving backboned animals that possess the organs of true flight. Apart from this specialisation for a life in the air the Bats are very similar in their organisation to the Insectivora, and long ago Huxley pointed out that they were exceedingly modified Insectivora; but this modification marks them off sharply from their nearest allies, and the authorities have agreed that it constitutes a reason for setting them apart in a special order—the Chiroptera or wing-handed animals.

So complete has been the adaptation to an aerial life, involving both pairs of limbs, that they are no longer fitted for progression on the earth. The fingers of the hand have been so drawn out that they are longer than the forearm, and the middle finger is at least equal in length to the head and body, whilst the thumb has been converted into a hook by means of which the Bat can hang from any rough surface. Over these exaggerated finger-bones a broad web of skin has been stretched, and connected not only to the sides of the body but also to the hind legs as far as the ankle, and then nearly or quite to the tip of the slender tail. The effect of this great modification, whilst it creates a pair of great wings, is to render the hind limbs unfitted for ordinary locomotion, for these are so twisted out of the position assumed in quadrupeds that the knees are turned backwards. This is the cause of the awkward, shuffling movements of a Bat on the ground which make it quickly rise into the air or at least to climb some vertical surface.

Looking at the skeleton of a Bat, we shall find the vertebral column short, the neck short-boned but broad, the spinal cord being of great thickness at this part though reduced to a mere thread at the hips. The ribs are usually flattened and connected to a strong breastbone, which has a prominent keel for the attachment of powerful muscles controlling the wings. The tail controls the web connecting the hind legs, which acts as a rudder in flight and as a net helping to capture and retain the larger insects upon which the Bat lives.

The permanent teeth—which are quite different from the milk-teeth—vary in the different species, but they always have distinct roots, and in the British species the upper surface always runs into points or cusps, suited for cracking the chitinous shells of beetles.

The Bat's brain is considered to be of a low order; yet its senses are very acute. Spallanzani, in the latter part of the 18th century made a number of experiments on Bats, depriving them of sight, smell, and hearing, and observing their behaviour under such conditions. He found that when released in a room across which he had stretched numerous threads to block their flight, they in every case avoided these, even when directly in their course. They appear to be helped in this matter by the sensitive whiskers around the muzzle, as well as by the delicate membranes constituting the wings and the outer ears. In the Horse-shoe Bats there is also a great development of the appendages to the nose, known as the nose-leaf, which act as delicate organs of special perception.

In most of the genera there is considerable development of the ear as compared with other mammals. The little lobe that guards the entrance to the ear in the human subject, and is known as the tragus, is much elongated in the Bats so that it becomes a conspicuous feature, and its variation affords one of the characters for identification of the species. Our two Horse-shoe Bats alone are without any prominent tragus.

It is considered that the Bat's powers of flight are superior even to those of the birds. This is especially evident if we watch the rapidity with which it can change its speed, suddenly stopping when in full flight, then making sudden swoops and turning somersaults in a way that would evoke the admiration of the stunt-loving airman. The females as a rule have larger wings and heavier bodies than the males.

Perhaps to the majority of people the Bat appears to be a creature without a voice. It does, however, utter a shrill squeak which is so highly pitched that many human ears are incapable of perceiving it. On the other hand, the Bat has similar deficiencies; and it has been proved that low notes, however loud, make no impression on the Bat, though a sharp clicking sound or the tearing of paper will alarm him at once.

Our Bats are all nocturnal in their habits, though a few indulge in occasional flights by day. Most of them have definite hours for flight, the time depending upon the flight period of the insects they prey upon particularly. They retire for the day into dark situations, such as hollow trees, caves, outhouses, or under roofs. In these sleeping places great numbers often congregate, and several species may be represented. During bad weather—when, of course, their insect prey also remains under cover—they do not leave their daytime shelter. When asleep their body temperature falls considerably. In harmony with this nocturnal habit we find that our Bats are usually dull coloured—some tint of brown with the underside lighter than the upper.

All the British species hibernate, and before the beginning of this period they develop a good deal of fat to carry them through it. On any day in the winter when there is any considerable rise of temperature they wake at once and look around for insects that have been aroused by the same means. The larger kinds usually eat their food as they fly, but the smaller Bats rest for a few moments for this purpose. The web between the legs and tail ("interfemoral pouch") is mostly used to hold their prey whilst it is being eaten. It also serves to receive the newly born young.

The young Bat is born blind, but not quite naked. It at once clings to its mother's fur by means of its claws, and by its teeth to her nipple. Nursing mothers appear to form colonies apart from the others. The growth of the young Bat is rapid and it is soon fully covered with fur. Before it is a fortnight old it is able to leave its mother temporarily, but it does not lead an independent life until it is about two months old. Nothing certain is known about the age to which a Bat attains, but it appears to be about four years.

Until the present century there was an astonishing lack of knowledge of the life-histories of our native species; but a small but enthusiastic band of observers have in recent years done much to make good the deficiency. In this connection the work of Messrs. Alcock, Coward, Moffat, Oldham, Tomes and Whitaker calls for acknowledgment. They have hunted far and wide, exploring the sleeping places and hibernacula, in woods, caves, roofs and belfries, and have established—among other facts—that our Bats are more numerous in the south, becoming scarcer as we go west, and that there are few species represented in the fauna of Scotland. Most of the species appear to be common in some one or more localities, even if rare elsewhere; and the physical features of a district have a striking influence on their local abundance or scarcity, certain species being more discriminative in this respect than others. The presence of woods, water, and caves appears to be the most favourable condition governing their comparative plentifulness or scarcity.

The Bats were known generically in Anglo-Saxon times as Flittermouse and Reremouse, and these names may be met with still in certain localities; but to the general public the Bat is still a Bat without distinction of species. Although there are twelve distinct kinds that breed in the British Isles, for each of which the naturalist has had to invent an English as well as an international name, not one of these has got into ordinary use; so that it is impossible to get any precise information from those whose occupation gives them opportunities for observation.

Larger Horse-shoe Bat (Rhinolophus ferrum-equinum, Schreber).

We have two Horse-shoe Bats, distinguished as Larger and Lesser, and they are regarded as the lowest organised of our Bats. Their distinguishing feature as a genus is the absence of the tragus from the ear, and the presence of a leaf-like outgrowth of naked skin on the muzzle around the nostrils. The broad forepart of this forms the horse-shoe, a protruding central portion behind the nostrils is known as the sella, and behind it an erect tapering portion is the lancet. There can be little doubt that this extraordinary expansion is no mere ornament, but a sense organ which enables these Bats to execute their marvellous flight through narrow passages. They are able even to distinguish invisible obstacles like glass, and they fly low down among bushes and herbage where they are far more likely to collide than in the upper air. In these respects their motions are different from those of the other Bats.

The Larger Horse-shoe Bat is a large and rather heavily built Bat whose proportions are only slightly exceeded by the Noctule (page 46), our largest species. The combined length of head and body is about two and a half inches, and of the tail an inch and a quarter. The forearm is two inches or more, and the expansion of the wings covers more than thirteen inches. The large ears are about half an inch broad, narrowing abruptly to the sharp recurved tip; when laid forward over the face they reach slightly beyond the tip of the muzzle. The lower portion of the broad wing membrane is attached to the ankle and the tail almost to the tip of the latter. The colour of the fur above is reddish-grey; on the underside pale grey. Its cry is a sparrow-like chirp.

The mouth has a straight broad opening below the swollen muzzle with its stiff moustache. The large canine teeth are very conspicuous in contrast with the small incisors. The dental formula for this and the next species is: i 1/2, c 1/1, p 2/3, m 3/3 = 32.

As already indicated, the flight of this Bat is usually low, and it alights to consume its prey, which it presses against the wing membrane, the interfemoral pouch not being large enough for the purpose. Its food consists chiefly of the larger beetles, such as cockchafers and dor-beetles, the quick-running ground-beetle Pterostichus, moths, flies, bees, and caddis-flies. It appears to be a thirsty creature, and may be seen lapping water. It takes its daytime sleep in caves, dark buildings, lofts and roofs. It may hang singly or crowd into crevices. Mr. Coward found it in the Cheddar caves hanging in bunches. Their overhead resorts are revealed by heaps of excrement below. Their natural resting attitude is hanging by the feet head downwards. They cannot walk on a flat surface, and before alighting on a vertical one they turn a somersault in the air to get the proper position. Their senses are so acute that Mr. Chas. Oldham says: "Even when sunk in winter sleep they appreciate a man's approach. The eyes are, of course, then shrouded by the wings, and the sense of danger must be conveyed to them either by hearing, smell, or, as seems to be most probable, by the exercise of their extraordinary tactile sense, which enables them to actually feel the approaching danger."

There is but one young at a birth, which occurs at the end of June or in July. Its eyes are closed, and the underside is quite naked and the skin purple. The eyes open about the tenth day. The Larger Horse-shoe Bat has an extensive distribution. From England it is found through Central Europe and the Mediterranean region, through the Himalayas to China and southern Japan. In our own country it is found chiefly in the South-west of England, South and West Wales, but does not occur in either Scotland or Ireland. The presence or absence of caves suitable for a winter retreat appears to have some bearing upon its distribution.

Lesser Horse-shoe Bat (Rhinolophus hipposideros, Bechstein).

The Lesser Horse-shoe Bat is much smaller and more delicately built than the species last described. The nose-leaf has a narrower outline and its sella is more wedge-shaped; the lancet slender with a wedge-shaped tip. The expanse of wings is less than ten inches, and the length of the forearm is only an inch and a half. The colour is much the same as in the larger species, but somewhat darker above and more yellow below. Its habits are similar also, but, naturally, it does not hunt such large beetles, nor does it fly so low. It has a more fluttering flight with intervals of gliding. Its "tchek-tchek" cry is of lower pitch than in most Bats, and Oldham compares it to a diminutive of the alarm-note of the Greater Spotted Woodpecker.

The single young one is born somewhat later than in the last species: it is born like the other with a thin coat of downy hair on the upper side only.

Males, apparently, are more numerous than females.

The species appears to be more abundant in localities where there are caves which provide it with the equable temperature it requires in hibernation. It is most susceptible to wind, and will frequently remain inactive in its shelter because there is wind outside. Even tame individuals exhibit a strong desire to get into the most retired corners and crevices. The first recorded British example was taken in a cavity over a baker's oven to which it had obtained access through a small fissure.

It may be considered a common species in the South of England from Kent to Cornwall, and more sparingly to Wales. It is unknown in East Anglia, rare in the Midlands, and its northward range terminates at Ripon. In Ireland it occurs in the West only, in some parts of which it is the commonest species. Its wider distribution includes Central Europe, Mediterranean, to Gilgit; northward in Europe to the Baltic.

Whiskered Bat (Myotis mystacinus, Kuhl).

The small and usually solitary Whiskered Bat was formerly considered to be a rare species, but it turns out that the naturalists of last century frequently confused it with the Common Bat—the Pipistrelle—which, however, is smaller and has a broader muzzle. The head and body measure about an inch and a half, and the tail the same length. The wings are narrow, but long, and have an expanse of nine inches.

The soft, long fur of the upper parts is light yellowish-brown in colour; lighter, almost dirty white below. It extends but slightly on the wing membrane, and there is little of it on the long, slender ear, whose outer margin is deeply notched, and the straight, tapering tragus half the length of the shell of the ear. The hinder margin of the brownish black wing membrane is continued to the base of the toes, and the spur (calcar) reaches halfway from the ankle to the long tail. Owing to the length of the fur on the face the small eyes are almost hidden and the face appears to be very short. There is a bristly moustache on the upper lip which has suggested its trivial and scientific names.

Though reputed to be of solitary disposition—and it usually enjoys its daytime rest apart from its kin—it has been taken in numbers on several occasions. It makes its appearance early in the evening, flying low along hedgerows, plantations, and cliffs, its method of hunting being not to chase flying insects in the air but to pick off such as have settled on leaves and twigs. It may also be seen at times flying in the daytime. It has a fondness for the neighbourhood of woods and water, where it finds many flies, beetles, and moths in flight. It is quite silent on the wing.

Mr. Oldham describes the flight of the Whiskered Bat as "slow, steady, and silent—I have never heard this species squeak on the wing. Individuals did not appear to wander far, but confined their attentions to single pools or short stretches of the stream, where they flitted about the alder-bushes or threaded their way with marvellous precision through the lower branches of the sycamore trees. I never saw one rise to a greater height than twenty feet, and often they flew within a few inches of the ground or skimmed the surface of a pool for a yard or two, only to rise again to resume their flight around the alders."

It is not very particular where it takes its daytime sleep. Any sort of shelter will do, whether it be a hollow tree or under a piece of loose bark, a hole in the wall, a roof, or behind window shutters. Its hibernation is passed by preference in a cave, whence it emerges for a flight whenever the weather is fine. In spite of its customary silence, it can produce a feeble squeak.

On the wing it is not easily distinguished from the Pipistrelle, which is so similar in size; but the noisiness of the Pipistrelle compared with the silence of the Whiskered Bat is the best guide.

The solitary young one is born in June or July.

It is widely distributed throughout England, with the exception of East Anglia. In Yorkshire it has been found at an elevation of 1400 feet. It appears to be common in Wales and Ireland, but rare in Scotland. It occurs all over Europe where there are trees, and extends eastwards to Asia. It is the smallest member of its genus.

We have three other representatives of the genus Myotis, which is probably the largest as it is the most widely distributed of all the genera of Bats. They are all of slender, delicate form, which is seen most clearly in the shape of the skull, the muzzle, the ear and its tragus. They agree also in having thirty-eight teeth—six more than in the Horse-shoe Bat. The dental formula of all the members of the genus is: i 2/3, c 1/1, p 3/3, m 3/3 = 38.

Red-grey Bat (Myotis nattereri, Kuhl).

The Red-grey or Natterer's Bat is somewhat larger than the Whiskered Bat, the head and body measuring about an inch and three-quarters, but the tail is relatively shorter, being only an inch and a half. It has the longest wings of our species of Myotis, their expanse being equal to eleven inches and a quarter.

The long, soft and dense fur is of a greyish-brown colour above and whitish on the underside. The wing membranes are dusky. It has a small head, with a narrow muzzle which is naked at the tip and slightly overhangs the lower jaw. The face is so densely covered with fur that the small eyes are hidden. There is also a moustache, and above the lips on each side is a prominent gland. The large oval ear is notched on the outer margin above the middle, and the long slender tragus is more than half the length of the ear, ending in a long, very slender point. The wing membrane extends to the base of the outer toe, and the interfemoral membrane is distinctly fringed with stiff hairs along its lower edge. The tail, which is carried extended behind, is slightly less than the head and body in length. The Red-grey Bat shares the Whiskered Bat's partiality for wooded districts, where it may often be seen in numbers, even before sunset. Unlike the last-named species it is both sociable and gregarious, and its daytime retreat in holes in walls, hollow trees, and caverns, is shared with Bats of its own and other species. It flies low, with a slow, steady flight, and often picks flies and small moths off leaves and twigs. When so engaged like the Whiskered Bat it may be known from it by its noisy chirping. It will turn somersaults in the air in order to alight by clinging with its feet.

The solitary young one is born towards the end of June.

It does not appear to be a generally distributed species even in the South of England. Its range extends from Cornwall and the Isle of Wight to Durham and Norfolk. It also occurs in Wales and various parts of Ireland. In Scotland it has been reported from Argyll, Midlothian, and Montrose. It is a native of Central and Southern Europe, extending north to the south of Sweden.

Bechstein's Bat (Myotis bechsteinii, Kuhl).

Bechstein's Bat has a general resemblance to the Red-grey Bat, but is slightly larger, with ears almost twice the breadth of those of that species, and the feet relatively as well as actually larger. Though the skull is larger, it is actually narrower than in that species. The thin ears are relatively larger than those of any European Bat, except the Long-eared Bat, where, however, they are of quite different shape and are connected by their lower margins, whilst here their bases are widely apart. The form of the ear is like that of the Whiskered Bat; so is the tragus, and the shape of the wings.

It is covered with soft, woolly fur, which is a greyish-brown on the upper parts and buff-grey below. The membranes are dark brown; that of the wing arises from the base of the toes, and that of the interfemoral leaves the last joint of the tail free.

The combined length of head and body is about two inches; of the tail an inch and a half. The ears are about three-quarters of an inch in length and half an inch wide; the tragus half the length of the ear. The expanse of the wings is ten inches. The single young is born about midsummer.

Bechstein's is the rarest of British bats, and so far has been recorded only from the South of England, the localities being the New Forest, Isle of Wight, Sussex, Berkshire, and Oxfordshire. Our knowledge of its habits is derived chiefly from the Continent, where it flies about woods, orchards, and the neighbourhood of dwellings, coming out from its retreat late in the evening and flying slowly and low over lanes and woodland roads, but only in calm weather. It is restricted to Central and Southern Europe.

Daubenton's Bat (Myotis daubentonii, Kuhl).

Daubenton's or the Water Bat was formerly considered one of our rarest Bats, but is known now to be one of the most widely distributed and plentiful species. It had probably been mistaken for the Common Bat or Pipistrelle to which it comes near in point of size, though its habits are different. It keeps close to the water, especially to some alder-sheltered pool in the river where there are plenty of caddis-flies and other insects. There from an hour before sunset it flies slowly in circles, frequently dipping its muzzle into the water to pick up surface insects. In such places the evening fly-fisher sometimes finds this Bat caught on his hook. It appears to be on the wing all night. It was probably to this Bat that Gilbert White referred in his eleventh letter to Pennant, when he said: "As I was going, some years ago, pretty late, in a boat from Richmond to Sunbury, on a warm summer's evening, I think I saw myriads of Bats between the two places; the air swarmed with them all along the Thames, so that hundreds were in sight at a time." This was long before it had been distinguished as a distinct species, and when it would probably have been regarded as the Common Bat.

It is clothed with short, dense fur, of a grizzled warm brown colour on the upper parts, and lighter brown or buffy grey, sometimes so pale as to show a distinct line of separation along the sides from the angle of the lips to the thigh. The face is dusky, and the ears and wing membrane are of a reddish dusky tint. The interfemoral membrane is whitish below, and there are whitish hairs on the toes. The membrane arises from the middle of the foot.

In size it is a little larger than the Whiskered Bat and the Common Bat, but smaller than Leisler's Bat. The head and body measure about two inches, the tail an inch and a quarter, the ear half an inch; the wing expanse is about nine inches. The foreleg and foot are conspicuously large. The ear has a rounded tip, and a shallow concavity on the upper part of the hind margin; the lance-shaped tragus is about half the length of the ear. The spur or calcar of the foot extends three-fourths of the distance between the foot and the tail. The last two joints of the latter usually extend beyond the membrane.

For its daytime rest it retires to crevices in trees, walls, caves or roofs, often in numbers, but its resorts have not the evil smell that such places frequently give off. It has a low soft chirp, less shrill than the cry of the Common Bat. In hibernation—which extends from the end of September to about the middle of April—it is no longer sociable, but hangs alone in some dark cave.

There is a single young one, born in June or July.

Its range extends from Ireland to Asia, and from the Mediterranean to central Norway.

Common Bat (Vespertilio pipistrellus, Schreber)

The Common Bat is in a general sense familiar to everybody, for it may be seen in the evenings flying everywhere, even in the streets of crowded cities. Its British distribution extends from the South of England to Scotland and the Hebrides and westward to Ireland. Its wider range includes Europe and parts of Asia. It is the smallest of the British Bats.

In spite of its small size—the head and body measure little more than an inch and a half—the Common Bat is of robust build, and it has a wing expanse of over eight inches. It has a flat broad head with a blunt muzzle and wide mouth. The short, broad ears are somewhat triangular with blunt tips. The erect, slightly incurved tragus has a rounded tip which does not reach quite to half the height of the ear. There are glandular swellings on the muzzle between the nostril and the small, but rather prominent eye. The tail is little over an inch in length, and the legs also are short. The last joint of the tail is free from the membrane and prehensile, and the Bat makes use of it as a support in crawling up or down. The spur reaches more than halfway to the tail. The narrow wing is attached to the middle of the sole of the foot.

The somewhat silky fur is a reddish-brown on the upper parts, slightly paler beneath. The wing membrane and the ears are blackish.

It is a very active Bat, flying over farmyards and gardens and about houses, frequently uttering its shrill little squeak as it snaps up the flies and small beetles, pouching and eating them without alighting. It continues its flight all through the night, and has a longer period of activity than any other species, for it leaves its hibernaculum in March and does not retire until winter has begun. Even then, a moderately high midday temperature is sufficient to awaken it and bring it out for an hour's hunt. It is this habit that accounts for the letters in the daily papers from City gentlemen who report the presence of a Bat flying along Cornhill or Cheapside early in January.

It is not particular in regard to its sleeping place, and is frequently found under roofs, behind rainwater pipes and gutters, or in any crevices between woodwork and brickwork in buildings. Any regular dormitory acquires a very fetid odour from its use.

The dental formula of the Common Bat is: i 2/3, c 1/1, p 2/2, m 3/3 = 34. Schreber's name of Vespertilio pipistrellus was bestowed in 1774 and is the oldest name; in the British Museum Catalogue it is Pipistrellus pipistrellus, a combination invented by Miller in 1897.

Serotine (Vespertilio serotinus, Schreber).

The Serotine and the Noctule are our two largest Bats, and in the early records they were very much confused. Though similar in size, they may be known apart by the shape of the ear; in the present species oval-triangular with the tips rounded. The fur is also of a darker brown, and there are other points of difference, such as the possession of two additional teeth by the Noctule. But for a few records of its occurrence in Essex, it might be said to be restricted in Britain to that portion of England bounded by the river Thames and the English Channel. A few examples have been taken in Cornwall, and other counties in which it is found are Surrey, Hampshire, Sussex, and Kent. It occurs throughout the Isle of Wight—where it is known as Rattle-mouse—but Kent is its British metropolis, where it is the commonest Bat. It extends through Central and South Europe, from Denmark to the Mediterranean and eastward into Asia.

It has a somewhat swollen face with little hair on the front portion, save for a moustache on the upper lip; but owing to the dark skin of the face the lack of fur is not very noticeable. The dark brown fur of the upper parts is soft and dense; behind the shoulders the hairs have buffy tips. On the underside the fur is somewhat lighter. There is little extension of fur on the wing, except a line of down on the under surface of the forearm. The membrane is attached to the base of the toes. The head and body measure about three inches, and the tail slightly exceeds two inches, the last joint being quite free of the membrane. The expanse of the wings is fourteen and a half inches. There are prominent glandular swellings on the muzzle. The ear is about three-quarters of an inch long; the short tragus—less than half the length of ear—has a straight front border and a curved hind border, with rounded tip. The canines and the inner incisors of the upper jaw are noticeably large and strong. Dental formula: i 2/3, c 1/1, p 1/2, m 3/3 = 32.

The Serotine makes its appearance in public about sunset, apparently retiring early and flying again in the early morning. It frequents glades in woods, and preys upon beetles and moths. In May and June large numbers of cockchafers fall victims to it, and in July and August in Kent and Sussex it plays havoc with the local Brown-tail Moth. In the early part of its season it flies at a low height, but later it prefers an altitude between thirty and forty feet, from which, however, it frequently descends to the ground. The change is, no doubt, connected with the seasonal succession of insects with different habits. It is a sociable species, and when it retires to holes or roofs for its daytime rest it is usually in company. Its hibernation begins at the end of October. Its voice is a squeak.

The Parti-coloured Bat (Vespertilio murinus, Linn.) is sometimes enumerated among British Bats, but on the strength of only two specimens captured in this country, in the "thirties" of last century. As one of these was taken at Plymouth and the other at Yarmouth, it is reasonable to suppose that they were mere stragglers which had reached our shores on board ship. Had they occurred as residents their distinctive coloration—dark brown upper side mottled with yellow-brown and whitish underside—and large size, would have established their identity at once.

Great Bat (Nyctalus noctula, Schreber).

Though similar to the Serotine in size and to the Pipistrelle in form, the Great Bat or Noctule was recognised as a distinct species long ago. We might with great fitness call this White's Bat, for it was the Selborne naturalist who first called attention to it as a native species, under the name of altivolans, suggested by its high flight. Schreber, however, had some years previously named it noctula, basing his description upon a French specimen. White refers to it several times, and in his xxxvith letter to Pennant gives particulars which the latter included in his "British Zoology." Part of White's description is worth quoting. He says: "In the extent of their wings they measured fourteen inches and a half; and four inches and a half from the nose to the tip of the tail; their heads were large, their nostrils bilobated, their shoulders broad and muscular; and their whole bodies fleshy and plump. Nothing could be more sleek than their fur, which was of a bright chestnut colour.... They weighed each, when entire, full one ounce and one drachm. Within the ear there was somewhat of a peculiar structure that I did not understand perfectly! [? tragus] but refer it to the observation of the curious anatomist. These creatures sent forth a very rancid and offensive smell."

To add to White's description, it may be said that the general form is robust and heavy, the forearm massive, the wing long and slender, its narrowness being due to the shortness of the fifth finger. The lower leg is short and thick and the foot broad and powerful. The muzzle is broad and has a glandular swelling between eye and nostril. The nostrils project forward and outward and there is a distinct concavity between the two crescent-shaped orifices. The ear is short—when flattened it is broader than long—with the front border rounded to the tip; its inner surface covered with short hairs. The ears are far apart. There is a very short, downy, bow-shaped tragus, broader above than below. The long, soft, golden-brown fur is abundant, and extends over the face and a short distance over the wing; it is paler and duller on the lower parts. On the underside there is a narrow band of fur below the arm bones. The last joint of the tail is free. The membrane and ears are blackish.

The dentition is: i 2/3, c 1/1, p 2/2, m 3/3 = 34.

The Great Bat, as one would expect from the shape of the wings, has a quick, dashing flight reminding one of that of the Swifts, with which, indeed, it may be seen high in the air hawking for the same prey. It often glides down obliquely on expanded wings. It flies at twilight and again at dawn, as well as in the daytime occasionally. It has a shrill, clear, cricket-like voice.

Mr. C. B. Moffat says they "cram themselves to bursting point either once or twice in the twenty-four hours, during a seventy minutes career of mad excitement among the twilight-flying beetles and gnats." They also take moths and other insects; but in captivity they have resolutely refused to eat such "warningly coloured" species as the Cinnabar and Magpie moths. It is proved that at one meal they will consume food equal to a fourth of their own weight. When one considers the lightness of insects the amount of good these purely insectivorous creatures effect is obvious.

Their resorts are in hollow trees and under the eaves of buildings, where numbers may associate together, especially in hibernation. Their presence is often indicated by thick layers of excrement. The Great Bat flies all through the year with the exception of January and the latter part of December. Pied and almost black variations from the normal colouring have been recorded.

The sexes are said to separate into distinct colonies in the summer: the females retiring to trees. The single young is born naked and blind towards the end of June. When they get their fur they are much darker than the adults.

Although the Great Bat is generally distributed as far north as Yorkshire, Durham, and the Lake District, it is common only in the South of England, from Norfolk to Cornwall, but is rare in the Isle of Wight. It is not recorded from Ireland. Formerly, it was not considered a native of Scotland, but in recent years several examples have been captured there. It is found throughout the greater part of Europe and adjacent parts of Asia.

Leisler's Bat (Nyctalus leisleri, Kuhl).

It is not necessary to give a detailed description of Leisler's or the Hairy-winged Bat, for it is a miniature edition of the Great Bat in a darker binding. The length of the head and body is two and a half inches and of the tail an inch and a half. The wing expanse is thirteen inches and a quarter. The fur on the upper parts is a darker brown than that of the Great Bat, but it is lighter on the under parts. The skull is only half the size of that species, and the entire build is lighter and less massive. Owing to this difference in size it is not so likely to be mistaken on the wing for the Great Bat as for the Common Bat. It is without the strong odour of the Great Bat. It agrees with the latter in its high flight, but its movements are not so swift and are more zigzag.

It is one of the rarest of our Bats, and like the Great Bat a woodland species, making its dormitory preferably high up in a decayed oak, but also in the roofs and crevices of buildings. Its period of activity begins about the third week in April and lasts until near the end of September, when it goes into hibernation, but a little mild weather in winter will wake it up and bring it out for a flight. According to the observations of Mr. C. B. Moffat it flies for about a hundred minutes just after sunset, and for a similar period just before sunrise. Its food consists of flies, beetles, and moths. Dr. Alcock, who has brought this Bat down by shooting it an hour after sunset, found it so crammed with food that it did not appear physically possible for it to feed longer.

The distribution of Leisler's Bat does not agree at all with that of its near ally, the Great Bat. It has been obtained chiefly in the Valley of the Avon (Warwickshire); also in Yorkshire, Cheshire, and Norfolk. It does not appear to occur in Scotland; but it is reported as abundant in several parts of Ireland. It is a purely European species, occurring only from Central Europe westward.

Long-eared Bat (Plecotus auritus, Linn.)

The Long-eared is probably the best known of our Bats owing to the very distinctive character afforded by the huge ears, which are as long as the forearm and longer than the body. In addition, it is one of the commonest and most widely distributed of our Bats, and likely to be met with anywhere in the British Islands. It is, however, rarer in the North of Scotland than elsewhere. It is found nearly all over Europe.

The large and mobile ears give this Bat an appearance of size not justified by its small and delicate build. The head and body combined measure less than two inches, whilst the tail is only a fraction less than that measurement. The fact that no other European Bat has such an equipment renders a detailed description superfluous, for the ears at once distinguish this from all the other species. These ears have their bases joined across the forehead. Their form is a long oval with rounded tip. Except for fringes on the folds they are hairless. They are semi-transparent and have transverse folds. The tapering tragus is nearly half as long as the ear, and might be mistaken for it when the Bat hangs asleep; for then the ears are carefully folded and tucked away in the wing whilst the tragus sticks out beyond the inanimate-looking bundle. Sometimes, when awake, one ear is held at a different angle from the other; but in flight both ears are directed forward. Often, when it has caught an insect, the Long-eared Bat will come to the ground to eat it.

The soft, silky, brown fur is long and thick, especially on the shoulders, but does not extend far upon the wings. On the under parts it pales to yellowish or dirty white. The wings are both long and broad, and their expanse in flight is about ten inches. The long tail when folded forwards can touch the top of the head; its tip is slightly free from the interfemoral membrane, and when the Bat hooks itself up head downwards for sleep it serves as a third foot.

The Long-eared Bat is found chiefly among trees, though it frequently comes into open windows at night when its hunting is over. It flies among the branches of trees and examines the foliage for insects of all kinds. In early spring, when the sallows are in bloom and attracting swarms of insects, the Long-eared Bat is there also: fresh from hibernation and with a keen appetite. He hovers like a hawk over a favourable tree, and swoops down upon his selected prey. He appears in the evening usually about half an hour after the sun has departed, and apparently feeds during the greater part of the night; occasionally he is active in daylight. He appears to be at least partially migratory, for it has been observed that in summer a swarm will appear in a district where they are not noticeable as a rule, and after staying a few weeks disappear.

The single young one is born in June or July. They are often found hibernating in clusters under house-roofs; but solitary individuals are also found in hollow trees and similar situations. Should the thermometer register 46° F. or more at any time during the winter, the Long-eared Bat awakes and makes a foraging flight—calling attention to his presence by his acute, shrill cry.

The dental formula is: i 2/3, c 1/1, p 2/3, m 3/3 = 36.

Barbastelle (Barbastella barbastellus, Schreber).

One feels inclined to apologise for the poverty of language displayed in the heading above; though no one accepts responsibility for it—the fault lies with the Law of Priority. A strong point in the Linnean System of nomenclature was its binomial character—there were two words only in the name of every animal and plant, the first of the two indicating the genus in which it was grouped, and the second peculiar to the species. In recent years the extension of our knowledge of the world's fauna has led to the breaking up of many of the older genera and a regrouping of the species. In some cases the species name has been adopted to denote a new genus, and then the Law of Priority steps in and says the oldest species name must be retained, so that instead of a binomial we get a mere duplication. When this happens—as above—to be essentially the same as the only "popular" name the species has ever had the result is ludicrous.

Daubenton, who first described it (1759), called it the Bearded Bat (La Barbastelle) owing to tufts of black bristles on the glandular swellings on the muzzle. It is of slender form with long legs and small feet. The irregularly four-sided ears are relatively large, as broad as long, and united by their bases just behind the muzzle. The outer border has a deep notch; the lance-shaped tragus is half the length of the ear. The nostrils open in a naked depression. The long, soft fur is a very dark brown, but many of the hairs on the upper surface have pale tips which produce a frosted appearance; on the lower surface such light tips are more numerous, and are specially evident along the middle line of the abdomen. The wing, ear, nose, and foot are dusky, appearing lighter than the furred regions.

The head and body measure about two inches, and the tail an inch and three-quarters. The expanse of wings is about ten and a third inches. This and the Long-eared Bat are the only British species whose ears connect; and the form of the ear in each is so distinct that there is no danger of confusing them. It is both solitary and silent in flight, which begins early in the evening, often in daylight; it holds its feet far apart and the tail decurved. In fine weather it flies high. During its diurnal rest it has been found in various retreats, often in company: under thatch of a shed, between the rafters and tiles of outhouses, behind a cottage shutter, in the crevices of walls and trees. Its voice is a metallic squeak or a buzz.

It has one premolar less on each side than the Long-eared Bat, so that its dental formula stands thus: i 2/3, c 1/1, p 2/2, m 3/3 = 34.

As a British Bat, the Barbastelle is found chiefly in the South of England, though it has been recorded from all the English counties between the Severn and the Wash; also Lincoln, Cheshire, and Cumberland (Carlisle). It appears to be absent from Scotland, Ireland, and the Isle of Man.