In vain through every changeful year Did nature lead him as before; A primrose by a river's brim, A yellow primrose was to him, And it was nothing more. At noon, when by the forest's edge He lay beneath the branches high, The soft blue sky did never melt Into his heart; he never felt The witchery of the soft blue sky. Wordsworth. To him who in the love of Nature holds Communion with her visible forms, she speaks A various language. Bryant. I SIGNS ON THE BEACH |
Ceramium | C. rubrum | |
C. strictum | ||
C. diaphanum |
The genera of an order are then placed within a cover and labeled in the same way, the legend then having the name of the order on the left and the genera on the right of the bracket,[†] thus:
RhodymeniaceÆ, suborder CeramieÆ | Callithamnion | |
Griffithsia | ||
Ceramium |
When the order is a large one the genera are distributed through as many covers as may be necessary. The covers are then arranged on shelves in the regular order of their classification, and each shelf is labeled with the order it contains. Herbarium-sheets cost at retail one dollar per hundred. Genus-covers cost at retail one dollar and eighty cents per hundred.
The first great biological division is into kingdoms, namely, the animal kingdom and the vegetable kingdom. Then by classification the vast number of existing animals and plants are grouped so as to give each individual a definite place. By this system a beautiful order is established, which enables the student to find any particular animal or plant he may wish to study, and also to know its general characteristics from the name of the group to which it belongs.
In broad generalization, objects of wide dissimilarity are recognized as belonging to the same kingdom, as do trees and grasses, or as do birds and fishes. Certain trees or grasses and certain birds or fishes have such points of resemblance that they plainly show that they belong to subdivisions. The most untutored people recognize these distinctions, but the naturalist goes further and finds points of distinction which the casual observer overlooks.
The animal kingdom has a varying number of divisions, called branches, subkingdoms, or phyla. Some late authors have admitted twelve divisions, and have given them the name phyla. Each phylum is composed of a group of animals with a plan of structure which is common to themselves, but differs from that of the animals of all other phyla.
The higher animals begin with the twelfth phylum, namely, the Chordata, or vertebrates. These animals have a spinal column, or series of vertebrÆ, while the lower animals, or invertebrates are without a spinal column, and depend for stability
An animal is classified in accordance with its morphology, anatomy, histology, and embryology. Morphology determines its general shape, the position of its limbs, eyes, and mouth, and the covering of its body; anatomy, the arrangement of its internal organs, such as the position of its heart, lungs, stomach, etc.; histology, the character of the tissues of the body; and embryology, the method of the development of the animal from the embryo to maturity. It is only after these exact discriminations have been made that the groups are arranged. Owing to the greater accuracy resulting from histology and embryology (methods which have been employed only in later years), many changes in classification have been made, and as science advances will continue to be made.
The primary groups are based on broad general characteristics, but their divisions and subdivisions are determined by closer distinctions. Animals having shells differ from those having a cartilaginous or those having a crustaceous covering, and are placed in different groups. Yet mollusks having a single or a double shell, having spiral or flat forms, living on land, in fresh water, or in the sea, while differing from one another, are all of one group. Lobsters and crabs, although both have crustaceous coverings, are very unlike; and again, there are many species of both lobsters and crabs.
To group individuals, noting resemblances as well as differences, a system of classification has been arranged with the following divisions:
Kingdom, Phylum, Class, Order, Family (or Suborder), Genus, Species.
IV
ANIMAL LIFE IN ITS LOWEST FORMS
ANIMAL LIFE IN ITS LOWEST FORMS
The biological division, or discrimination, between animal and vegetable life, is based on the manner of assimilating food. Plants feed upon mineral substances, or, in other words, assimilate inorganic matter, while animal life requires for its support vegetable or some other organic matter.
Animal as well as vegetable life in its lowest forms begins with one-celled organisms, which are called respectively Protozoa (first animals) and Protophyta (first plants). Both of these divisions are composed mostly of microscopic objects, and, together with other minute forms of life of the marine species, constitute a great part of the plankton, or free-floating organisms of the sea. These minute organisms seem like connecting-links between the two kingdoms. They were claimed by both botanists and zoÖlogists until the use of the microscope made close observation of minute structure possible.
Among the small animalcules of the phylum Protozoa are some which are familiar to all by name, such as the Infusoria, which are most interesting creatures to examine in a drop of water under the microscope. A more tangible example of the Protozoa are the Foraminifera. Foraminifera, like diatoms, have a shell-like covering, and these shells, among the most plentiful of which are those of the genus Globigerina, fall, as do those of diatoms, in immense numbers to the bottom of the ocean, and form respectively what are known as Globigerina and diatomaceous ooze. In course of time the sedimentary strata become fossilized; thus, the stone of which the city of Paris is built consists of fossilized
Many of the lower animals resemble plants in form. Hydroids and polyzoans are often gathered and preserved as seaweeds. Corals, sea-anemones, and holothurians are curiously like plants. For a time the confusion about the division of animals and plants was partly owing to this resemblance of forms, and the theory of the animal nature of corals was for a long time considered to be refuted by the testimony of a naturalist who declared that he had seen them in bloom. Later this class of animals was believed to occupy an intermediate sphere and partake of the characteristics of both kingdoms. The name zoÖphyte, meaning "animal-plant" or "mingled life," was adopted because of these resemblances and was formerly applied to these forms only. To-day it has a broader application. There is still a neutral class, called Protista, comprising organisms which have not yet been classified as plants or animals.
V
DISTRIBUTION OF ANIMAL LIFE IN THE SEA
DISTRIBUTION OF ANIMAL LIFE IN THE SEA
All living things which inhabit the sea have their appointed boundaries, and the localization of marine life is as distinct as is that of terrestrial life. Each kind of beach has forms of life peculiar to itself. Those animals which inhabit rocky shores or stony beaches or sand or mud may be looked for anywhere under similar physical surroundings. They are, however, modified by climatic conditions, and in wide ranges differ in genera and species. The rocky coast of Maine has a class of sea-urchins and starfishes which are different from those which live on the rocky shores of the northern Pacific coast, yet they are all easily recognized as belonging to the same family, and a description of typical forms is a sufficient guide to the recognition of their relationships.
A bathymetrical division defines the classes of animals according to the depth of water in which they live. Those which live near the shore are littoral species, those of the broad sea are pelagic, while those living at great depths are abyssal.
Their modes of life are distinguished by other terms. Those which float at or near the surface and are carried about by the currents, like the jellyfishes and the minute organisms mentioned elsewhere, are plankton. Strong swimming animals which move about at will are nekton. Those which are fixed, like oysters, sponges, etc., and those which crawl on the bottom, like crabs, echinoderms, etc., are benthos.
Again, geographical divisions are named, in recognition of climatic influences. The boreal fauna and flora on the Atlantic
The shore or littoral fauna is especially abundant and comprises more species that are curious in form and beautiful in color than the others. The invertebrates of the deep sea are mostly transparent and of a blue or violet tint, while the fishes are gray or bluish above and white beneath, which renders them inconspicuous to their enemies.
VI
SOME BOTANICAL FACTS ABOUT ALGÆ
SOME BOTANICAL FACTS ABOUT ALGÆ
The vegetable world is separated into two great divisions: thallophytes, or plants having no distinction of leaf or stem, and cormophytes, or plants which have leaves and stems. All thallophytes that live in the water and are nourished wholly by water are called algÆ.
A second great division of plants is into cryptogams, or those that have no flowers, and phanerogams, or those that have flowers, by means of which seeds are produced and successive generations of plant life continued.
Thallophytes and cryptogams comprise the lowest and simplest vegetable organisms. AlgÆ belong to both these divisions; to the first because they have neither stems nor leaves, and to the second because they have no flowers.
The lowest forms of algÆ are microscopic in size, each individual being a single cell; but in the ascending scale they attain curious and beautiful shapes, some growing to a gigantic size and in forms that resemble shrubs and trees. The green surface commonly seen on the shady side of trees, on stone steps, and in other damp places is one of the species of algÆ which consist of a single cell. This plant or cell divides, and the separate divisions divide and subdivide again and again, and in time the aggregate number is great enough to spread over a comparatively large surface, and thus become visible to the naked eye. This plant, the Pleurococcus vulgaris, is a fresh-water alga. The Protococcus nivalis, or red snow, described on page 33, is a closely allied species. The green and blue-green scums and slimes on
The vegetative body of a thallophyte is a thallus, and corresponds to stem and leaf. It is also called a frond. What corresponds to the root of flowering plants is in algÆ a disk or conical expansion of the base of the plant. It is simply a holdfast by which the frond attaches itself to any submerged material. The algÆ which grow on sandy shores and on corals have holdfasts which branch like fibrous roots and penetrate porous substances in all directions; but this is only for greater stability, and is an adaptation to the habitat. Holdfasts do nothing for algÆ other than the name implies, whereas real roots absorb the nourishment upon which plants live. AlgÆ are nourished by the substances held in solution by the water which surrounds them.
AlgÆ are the lowest and simplest in organization of all plants, because they are composed of but one class of cells, such as in flowering plants are called the parenchyma, or soft cells, these being the ones which compose the pulp of the leaf. In the lowest orders of algÆ single cells constitute individual plants, as in Pleurococcus; but in the higher forms, such as Sargassum, they arrange themselves in such a variety of combinations as to resemble plants which have leaf and stem. The botanical distinction is that in leaf and stem there would exist the woody and the vascular cells as well as the parenchyma cells.
Beginning with plants composed of a single cell, the next development is into filamentous plants, which are single thread-like rows of cells, as in Cladophora. In Ulva is seen the earliest type of an expanded leaf. The cells are here arranged in a horizontal surface of plate-like or ribbon-like shape.
In Ulva there is a double layer of cells. The layers separate in Enteromorpha, giving a hollow or tubular form. In Monostroma a double layer is opened or torn apart, giving a frond with a single layer of cells.
The stem-like forms of certain algÆ are composed of cylindrical cells which combine or grow in a longitudinal direction chiefly. Sometimes the cells are arranged evenly, in which case the stem seems articulated, as in some species of Ceramium. Again, they are irregularly placed, so that the stem appears solid.
The highest types of algÆ in the differentiation of parts, or vegetative forms, are to be found in the FucaceÆ, of the brown seaweeds; the highest in the reproductive development, in the red class.
Reproduction by cell-division, in which the organism itself breaks up into two or more individuals, is called vegetative reproduction. Higher forms reproduce by spores, or germ-cells, which give rise to new individuals on germination.
The substance of an alga is more or less firm, according as the vegetable mucus or gelatinous matter it contains has more or less consistency; it is membranaceous when the gelatine is scant and glossy, gelatinous when it is abundant and fluid, and cartilaginous when it is hard.
Some algÆ are annuals; a few are perennials, and cast off and renew their laminÆ every season. Many plants present quite a different appearance at different seasons of the year, and so are often difficult to identify. Those which form spores throw off these isolated cells, which sink or are washed to positions where they germinate and begin their cycle of life. Many of the spores begin their growth at once, without regard to season, so the species is ever present.
VII
NAMING OF PLANTS
NAMING OF PLANTS
The real or technical names of plants, which at first appear long and unpronounceable, are in reality simple when the system of naming is understood. Every plant has a generic and a specific name. The generic name is analogous to the surname of a person, such as Smith or Jones. The specific name is analogous to the Christian name of a person, such as John or James. The specific name never stands alone, and would have as little designating character as John—— or James——.
This is called the binomial (two-name) nomenclature. It was introduced by LinnÆus, and greatly simplified the system of naming. The rule in scientific nomenclature is that all names must be Latin or Latinized. This gives a universal language by which scientists of all countries understand one another.
The names of classes (the highest groups) and subclasses are adjectives or adjective nouns, expressing the most prominent characteristic of the class or subclass. Thus the four subclasses of the class AlgÆ are:
CyanophyceÆ (subclass of blue-green algÆ).
ChlorophyceÆ (subclass of grass-green algÆ).
PhÆophyceÆ (subclass of dusky-brown or olive-green algÆ).
RhodophyceÆ or FlorideÆ (subclass of red algÆ).
Orders are, with few exceptions, the names of genera with the termination -aceÆ, as:
UlvaceÆ, from the genus Ulva.
EctocarpaceÆ, from the genus Ectocarpus.
GigartinaceÆ, from the genus Gigartina.
Suborders, or groups between orders and genera, terminate in -eÆ. Names of genera are nouns or words taken as nouns. They are derived from any source,—from prominent or peculiar characteristics, from localities, or from names of botanists,—or they may be wholly arbitrary. Personal generic names are divested of titles and take a final a, or, in many cases, for euphony, ia. Thus, Ulva is the Latin for "sedge"; Ectocarpus is from two Greek words meaning "fruit outside"; Corallina means "coral-like"; Grinnellia is named for Mr. Henry Grinnell.
The specific names are commonly adjectives, but sometimes they are nouns, and occasionally are the names of the botanists who first described the plants, in which case the name terminates in -i or -ii. The specific name always follows the generic name, thus:
Ectocarpus Hooperi, a species of Ectocarpus, first described by Mr. Hooper.
Grinnellia Americana, a species, peculiar to America, of a genus named for Mr. Grinnell.
Griffithsia corallina, a species resembling coral, and belonging to a genus named for Mrs. Griffiths.
With regard to the four subclasses mentioned above, it should be said that algÆ are strictly classified in accordance with their methods of reproduction; but since allied species have, with few exceptions, the same color, the classification by colors is generally adopted as convenient and sufficiently precise.
Familiar, or, in technical language, "vulgar," names are very generally given to land plants, and especially to flowers; but seaweeds are less in sight than flowers are, and so, save in a few instances, have not been named except by the man of science. To remember the scientific names will not be found difficult, for without effort or special pains to acquire the new vocabulary, the names, like those of new personal friends, will insensibly become fixed in the memory.
In the body of this work each of the groups (class, subclass, order, etc.), in the classification of both animals and plants, is indicated by a special kind of type.
VIII
DISTRIBUTION OF ALGÆ
DISTRIBUTION OF ALGÆ
The eastern coast of North America has been divided into four sections, which correspond to the distribution of the algÆ which are characteristic of each section. The boundary-lines are not precise, since some species of each section extend beyond the defined limits; but arctic forms are not generally found south of Cape Cod, nor can tropical varieties be expected north of Cape Hatteras. On the intervening coast, however, there are some species common to both sections. The divisions are:
- (1) Greenland to Cape Cod;
- (2) Cape Cod to Cape Hatteras;
- (3) Cape Hatteras to Cape Florida;
- (4) the Florida Keys and the shores of the Gulf of Mexico.
On the Pacific coast such distinct lines of demarcation do not exist, there being no such natural barriers as are formed on the eastern coast, first by Cape Cod, and, second, by the stretch of sand-beach which extends from New York to Charleston, and which divides sharply the climatic varieties.
The whole shore is again divided laterally into three distinct belts, called the littoral, the laminarian, and the coralline zones. The first or littoral zone covers the space between tide-marks. Vegetable life in this zone is subjected first to exposure to the sun and air, and even to desiccation, and then to entire submergence at constantly recurring periods. The rockweeds (Fucus), which are so plentiful in this zone, are very gelatinous, nature having apparently provided the gelatine to protect the cells of the plant from the effects of the alternating extreme conditions. Fucus and Enteromorpha predominate in this zone.
The laminarian zone extends from low-water mark to the depth of fifteen fathoms. The LaminariaceÆ and the beautiful red algÆ (FlorideÆ) grow here.
The third or coralline zone extends to the depth of about fifty fathoms. The algÆ of this zone, the nullipores, are incrusted with a deposit of lime which gives them the appearance of corals; and, singularly enough, the corals, which are animal forms, simulate plant life.
Again, algÆ have special habits and demand certain climates and seasons for their growth. Algologists register the place where a specimen is found, and in this way localities have been pretty well determined. However, great exactness has not been reached, and the collector is ever watchful to find an alga in some undiscovered home within the given range. Although algÆ grow from extreme high-water mark to the depth of fifty fathoms, almost every variety may be found on the beach, those growing in deep water being frequently torn off and washed ashore by the waves. The heaps of sea-wrack will often reward one who examines them carefully for deep-water species. Seaweeds are most abundant on rocky shores, particularly where there are stratified rocks with crevices, which afford shelter from the waves. Rock pools often contain beautiful varieties of the more delicate species. Red algÆ will sometimes be found on the shady side of these pools. Sand-beaches are unfavorable to the growth of seaweeds, but fronds which have been carried long distances by the currents will frequently be found on such shores.
IX
SOME PECULIAR AND INTERESTING VARIETIES OF ALGÆ
SOME PECULIAR AND INTERESTING VARIETIES OF ALGÆ
The species of seaweeds that are known and classified are said to number several thousands. These plants, which have neither vessels for the conduction of fluids, nor fibers, consisting simply of the first vegetable element, the cell, have, notwithstanding this limitation, assumed a great variety of forms. In size they vary from one one-thousandth of an inch in diameter, the smallest green plants known, to those which exceed in length the height of the tallest trees and form dense submarine forests, which in places make comparatively deep water impassable for boats. In texture they vary from a jelly-to a paper-and a leather-like consistency. In color they have all the shades of green, brown, and red.
DIATOMS AND OTHER MINUTE ALGÆ
Among the smallest algÆ are diatoms. They are microscopic in size, but exist everywhere in both salt and fresh water, and are infinite in variety as well as in numbers. They have a silicious, shell-like covering, which divides and subdivides in their reproductive growth, forming varied shapes which are exceedingly beautiful and interesting to examine under the microscope. In vast numbers they float on the surface of the sea, and, together with other minute free-floating organisms, form the basis of food-supply for fishes. Their indestructible shells fall to the bottom of the sea, forming large deposits, which in time become fossilized. The city of Richmond, Virginia, is built upon
Associated with diatoms, in fresh water, are desmids, which are green in color and resemble the diatoms except in having a cartilaginous instead of a silicious covering. Another minute organism, Pyrocystis noctiluca, is luminous and is said to produce the beautiful phosphorescent effects seen in tropical seas. Trichodesmium is a little alga which periodically occurs in great numbers, giving the water a red appearance, as in the Red Sea, which is said to derive its name from this circumstance.
RED SNOW
In the high latitudes of the arctic regions, also on snowy mountains at altitudes where all vegetable life is supposed to be extinguished, there sometimes appears a redness on the surface of the snow, which in some cases extends for many miles. At a certain place in Greenland the color was so vivid that an arctic voyager named the locality the Crimson Bluffs.
The strangeness and almost sudden appearance of this color in the snow have been so unaccountable to uninformed observers that it has been ascribed by them to the falling of bloody snow and has been regarded with superstition. The redness is caused by the growth of one of the smallest of plants, the Protococcus nivalis. It is a simple one-celled alga containing protoplasm and endochrome (red coloring-matter). It grows by cell-division, the cell dividing into four, eight, or sixteen parts on a quaternary scale. Each part acquires a new covering while within the mother cell, and when it emerges it is a complete individual and ready to repeat the process. Only a few hours are required for its growth and development; hence its increase is rapid, and it requires but a little time to make itself manifest in those places where the conditions are favorable to its existence.
THE SARGASSO SEA
When the voyager reaches a certain region of the North Atlantic, called the Sargasso Sea, he sails into a vast undulating marine
This vast acreage of vegetation, as large as the continent of Europe, lying southwest of the Azores and extending between the Canary and the Cape Verde Islands, was first reported by Columbus, and takes its name from the floating plant of which it is composed, the Sargassum bacciferum, a species of the order FucaceÆ, commonly known as gulfweed. Columbus's sailors took fright at the marvelous appearance and wished to turn back, thinking they had reached the end of the navigable ocean. They thought, if land were beyond, it was guarded by shoals, and that the weeds concealed dangerous rocks. Columbus threw out two hundred fathoms of line, but did not reach bottom, and continued on his course for fifteen days before emerging into clear water. From that day to this the Sargasso Sea has attracted the attention of all navigators. It is especially interesting to scientists. The physicist finds there the phenomenon of the ocean currents holding in a vortex this immense mass of seaweed, the zoÖlogist finds a great pasture in whose protecting shelter are living and breeding countless numbers of marine animals, and the botanist is puzzled because the source of this species of plant is clouded with doubt.
According to one theory, the plants are dislodged by the tempests from terrestrial beds and carried by the Gulf Stream into the huge eddy; but since there does not exist enough of the attached plants of this species to supply the vast accumulation, another and more generally accepted theory is that the gulfweed lives also a pelagic life and adapts itself to the conditions of the
There are said to be one hundred and fifty species of Sargassum, but S. bacciferum alone constitutes the beds of the Sargasso Sea. The plant is the most highly differentiated of any seaweed, in that it more nearly approaches the true leaf and stem, and is described botanically as follows: Frond furnished with distinct, stalked, nerveless leaves and simple, axillary, stalked air-vessels. The integument is leathery, and the color brown of varying shades. The most striking peculiarity is the abundance of globular cells. These berry-like air-bladders give the plant buoyancy enough to support the weight of its innumerable guests. (Plate XVI.)
THE LAMINARIACEÆ
In the laminarian zone, described above, grow the LaminariaceÆ, an order of brown seaweeds, some of whose genera grow to enormous size, and in some places form dense submarine forests. Darwin speaks of the good service rendered by these plants to vessels navigating stormy coasts, where often they act as natural breakwaters, and again as buoys designating dangerous rocks near the shore on which they grow. The seaweeds belonging to this order, commonly known as oarweeds, tangle, devil's-apron, and sea-colander, are frequently seen twelve to twenty feet in length, and others are measured by fathoms. One of the giant plants is Nereocystis LÜtkeana, which occurs on the northwest coast. It has a stalk, sometimes three hundred feet in length, which bears on its extremity a barrel-or cask-shaped air-vessel, six or seven feet long, from the surface of which a tuft of fifty or more forked laminÆ grows to a length of thirty or forty feet. The stem which anchors this immense frond is so small that the Aleutian Indians use it for fishing-lines. The sea-otter makes his home on its huge air-vessel, and the plant is called by the Russians the "sea-otters' cabbage."
But the longest of all known plants is the alga Macrocystis. Its thin naked stem, the diameter of which seldom exceeds one quarter
Lessonia, another genus, resembles a palm-tree. It grows erect to a great height and has a stem like the bole of a tree. It branches in a forking manner and has depending from its branches laminÆ two or three feet long. The large stems from which the laminÆ have been torn by the storms, and which have been cast ashore on the Falkland Islands, as described by Sir Joseph Hooker, resemble driftwood, as they lie in piles three or four feet high and extending for many miles.
Agarum and Thalassiophyllum are arctic genera, but they are found within our limits, the former in the North Atlantic. It has a simple but enormous leaf-like frond. The latter, which is found on the North Pacific coast, has a compound frond. Both are characterized by their fronds being perforated throughout with holes, giving them the name of sea-colander.
X
USES OF ALGÆ
USES OF ALGÆ
Water covers two thirds of the surface of the earth, and algÆ, with a very few exceptions, constitute the whole vegetation which exists in that enormous area. They have, therefore, an important part to perform in the economy of nature. AlgÆ do not, like land plants, derive their nourishment from the soil to which they are attached, but from substances held in solution by water. In their growth they effect changes in the water analogous to those effected by land plants in the air; that is, they change so-called impurities in the water into materials essential to animal life. The function of plants is that of transforming or manufacturing inorganic matter, which they assimilate, into organic matter (such as starch, albumen, sugar), which forms their own structure and which is the food essential to animals. In this process, plants inhale carbonic acid gas which animals breathe out, and exhale oxygen which animals breathe in. Plants feed on mineral substances and furnish vegetable food, thus keeping up the balance of life.
Fresh-water algÆ have a like economic value. The green surface on stagnant pools is a vegetable growth whose function is to assimilate the matter which makes the pool offensive. A submerged district soon becomes covered with scum, or minute plants (SphÆoplea annulina), which grow with great rapidity, using up the materials of the decaying vegetation, and in great measure counteracting the ill effects, in the atmosphere, of such decay. When the waters subside, the plants shrivel up and appear like thin paper covering the ground. This ephemeral substance soon
AlgÆ, as has been said above, grow in definite zones, and each zone has also a definite animal life which finds there its food. Darwin says: "In all parts of the world a rocky and partially protected shore perhaps supports in a given space a greater number of individual animals than any other station." And speaking of the LaminariaceÆ, he adds: "I can only compare these great aquatic forests of the southern hemisphere with the terrestrial ones in the intertropical regions. Yet if in any country a forest was destroyed I do not believe nearly so many species of animals would perish as would here from the destruction of the kelp." The same may be said of the Sargasso Sea, where millions of living creatures make their home. In every kind of marine fauna there are species which derive, if not the whole, at least a part of their nourishment from the seaweeds.
The vegetation in the narrow boundary of the three zones is palpably inadequate to supply the needs of the animal life which exists in deeper waters. But over the broad area of the ocean there exists a vast number of pelagic, free-floating algÆ, which, although microscopical in size, are almost infinite in numbers. In illustration of this it has been estimated that, although they are not especially numerous in the Sargasso Sea, yet if all the seaweed there were gathered into one mass and the free-floating algÆ into another, the bulk of the latter would exceed that of the former. The pelagic flora consists of DiatomaceÆ, ProtococcaceÆ, PeridinieÆ, and others. Undoubtedly it is on these pastures that fishes feed, as well as other organisms which in turn are food for fishes.
Fucus and Laminaria constitute the kelp from which iodine is obtained, and were at one time the source of the potash of commerce. Fucus vesiculosus is a constituent of a medicine used as a cure for obesity. Chondrus crispus, commonly known as Irish moss, was a few years ago generally used as an article of diet. Porphyra vulgaris (laver) is used by the Chinese for soups. Rhodymenia palmata (dulse) is an article of food in Ireland and Scotland.
XI
COLLECTING AT BAR HARBOR
COLLECTING AT BAR HARBOR
The beautiful coast of Maine is a particularly good field for shore-collecting. The rocky coast harbors the boreal fauna and flora which depend upon such physical conditions, and the shores at Bar Harbor are typical of those found elsewhere in northern New England. The rocks give shelter from the beating surf, while life has exposure to the cold, pure waters of the arctic current. Everywhere along the shore, rock pools are to be found. These are perhaps the most fascinating of all spots to the collector. They are veritable gardens of the sea, where species flourish which naturally belong to deeper water, but which find in such pools conditions suitable to their existence.
At Bar Harbor one well-known and frequently visited rock pool is found in Anemone Cave. Entering a field at Schooner Head, one turns to the right and follows the rocky shore for two or three hundred feet. It is difficult to take this short walk without being constantly diverted and delayed by the various attractions one meets, such as the tide-pools, the barnacles which in places whiten the rocks, the periwinkles, the purpura shells, and the curious algÆ; but at last one arrives at a cavern under an overhanging rock. Here is a large tide-pool which at first sight displays only a beautiful scheme of color. It is carpeted with a bright-pink alga, Hildenbrandtia rosea, which incrusts the basin of the pool.
Interspersed with the pink are patches of a deep-red color, having a velvety appearance, which are formed by another crustaceous alga, Petrocelis cruenta. The water of the pool is of crystal
The fronds of the laminarian Alaria esculenta are tiny here, while just outside the cave they are to be seen several feet in length, beating against the rocks in the swash of the waves. Thorny sea-urchins (Strongylocentrotus drobachiensis) make green spots which look like tufts of moss. Yellow and green sponges in little cones are spread over small surfaces. Starfishes and ophiurans are plentiful. The Purpura lapillus and Littorina litorea and rudis (periwinkles), so plentiful on this coast, are present. The Mytillus and the Saxicava and the AcmÆa testudinalis are also to be found. A green crab (Carcinus mÆnas) is snugly hidden in a dark nook on the shady side of the pool, and many small crustaceans scuttle away from under stones as they are lifted. The collector is always anxious for uncommon, or rather less plentiful, species, and here are found two specimens of nudibranchs, or naked mollusks, Æolis and Dendronotus. The Chiton ruber, a jointed mollusk, was also found here, and five species of sea-anemones were counted. As this is a favorite hunting-ground, the anemones have not been left to attain full growth; but there are very many small ones which at first are not distinguishable, as they retract their tentacles at the slightest disturbance of the water and are then quite inconspicuous. After a little time of quiet watching they will be seen putting out their tentacles and expanding their beautiful flower-like forms. It is useless to try to capture them uninjured, so tightly do they adhere to the rocks, and the difficulty of preserving them in an expanded form is so great that amateur collectors had better leave them undisturbed to beautify the pool.
It was hard to resist robbing this rock pool, where the author in half an hour counted twenty different species, and finally left, feeling that its treasures were not half discovered; but collecting should be done elsewhere, and this pool be guarded as a gem to be admired and not to be despoiled.
This pool in Anemone Cave, although so very attractive, is surpassed in beauty and interest by pools on Porcupine Island, at the base of the cliff. This place is somewhat difficult of access, and the timid will not undertake the descent to it; but the enthusiastic collector, who overlooks small obstacles, will be repaid by a visit to this spot, where all the treasures of Anemone Cave are multiplied many times over. These pools are resplendent with large anemones, hydroids, nudibranchs, mollusks, echinoderms, crustaceans, and algÆ. Alaria esculenta, several feet in length, is beaten to a fringe against the rocks, and Agarum Turneri, the sea-colander, is also found here, together with beautiful specimens of Rhodymenia palmata, which is so plentiful that it reddens the rocks.
A Metridium marginatum, the most common sea-anemone of this coast, was taken here which measured six inches in diameter. This creature threw out so many of the processes used for defense that it seemed at first as though it were covered with some seaweed; but the worm-like movements of these threads, which measured six inches or more in length, soon disclosed their nature.
On the more accessible shores of Porcupine Island are found the naked mollusks (nudibranchs) Æolis and Dendronotus. Clinging sideways to the rocks just above high-water mark are many shells of Littorina rudis. They are fastened to the rocks by a glutinous deposit along the outer lip, and the peculiar exposure of the open end, as well as the position above tide-mark, indicates that this animal is undergoing transformation into a land species. Littorina palliata is abundant on the rockweeds (Fucus); some of the specimens are banded with yellow, and all closely simulate the seaweed on which they cling. Beautifully banded specimens of Littorina litorea are also plentiful. Among other shells which are abundant here as well as elsewhere on this coast are Purpura lapillus, AcmÆa testudinalis, Buccinum undatum, Mya arenaria, and Mytillus edulis.
Under the rockweeds in small pools and crevices are the polyzoans Bugula turrita and Membranipora pilosa, and the hydroids Sertularia pumila and S. argentea.
The seaweeds Rhodymenia palmata (dulse) and Desmarestia are plentiful; also beautiful worms, crustaceans, and starfishes.
A very interesting beach is found a few hundred feet south of Otter Cliffs, to which an easy descent is made if one follows a pathway leading to it through a grove adjacent to the drive. Here one will be interested in the study of numerous and beautiful rock pools.
Sea-urchins (Strongylocentrotus drobachiensis) seem to carpet some of them, having the appearance of mossy tufts. Beautiful pink and purple starfishes (Asterias vulgaris), brittle-stars (Ophiopholis aculeata), sea-cucumbers (Pentacta frondosa), sea-anemones, and crabs are abundant. If one lifts a stone the little crustaceans Orchestia and Gammarus will hurry away, and very likely an interesting worm or a nudibranch will be found. It is also most interesting to watch the barnacles, which are below the surface, reaching out their curled, feather-like feet in regular rhythmic grasping motions. The common mussels (Mytillus edulis), which in places blacken the shore, are beautiful under examination, and the silky network or byssus which forms the anchorage should be observed.
The rocks are hung so plentifully with Ascophyllum nodosum (rockweed) that its beauty is likely to be passed over unnoticed. On the Ascophyllum is growing in tufts Polysiphonia fastigiata; other seaweeds, Rhodymenia palmata, Chordaria flagelliformis, Desmarestia aculeata, Corallina officinalis, and Ceramium, are so abundant that one forgets to value them at the moment. Higher up on the beach the rocks are spotted with papery sheets, which, floated out in water, prove to be the beautiful purple Porphyra. A fine, dark colored, hairy scum on the rocks is Bangia fusco-purpurea. Sometimes one finds here fronds of Laminaria which have been washed ashore. Various green algÆ are abundant. Even if not collecting, it is well to carry a small tin pail to the beach and float out pieces of the algÆ in order to observe carefully, if but for a moment, the beautiful forms they have in their natural state. Watched for a few minutes in a pail of water animals disclose curious
Most of the various species mentioned above are common along the whole shore, and may be looked for at almost any point where the water is free from contamination.
At the sand-beach are found species which do not inhabit the rocky shore, as the sand-dollar (Echinarachnius parma), Polynices (Lunatia) heros, Mya arenaria, and others. After a storm various deep-water forms are washed upon this beach. Laminaria digitata, six feet long, is found here sometimes under these circumstances. Chordaria flagelliformis, resembling long switches of hair, floats from the rocks near the shore. To the left, on the rock under the overhanging ledge, is a tide-pool which one would hesitate to deface by touching a single specimen. So crystal-clear is the water, so brilliant the Hildenbrandtia, so lovely the Corallina, that all seem placed there to excite admiration.
But most of all one should obtain the permission of the owner to visit Rodicks Weir. Here is an immense natural aquarium, full of living wonders. On a clear day, sunlight penetrates to the bottom, and at low tide the whole contents of the weir are clearly seen as one floats through the inclosed water-spaces. On the bottom are sea-urchins, many of them with sticks or stones on their backs, which the animals have placed there in the endeavor to conceal themselves; starfishes feeding; and great numbers of whelks (Buccinum undatum). Cuttlefishes dart rapidly about, and skates, sculpins, and other fishes display their curious forms. Very likely a giant jellyfish (Cyanea arctica) is entangled in the brush, so that one can examine at short range its wonderful and beautiful parts. Other jellyfishes may be closely scrutinized.
The alga Polysiphonia violacea floats in long feathery tufts from the stakes.
On the eel-grass are to be found Lacuna vincta and the delicate iridescent little shells of Margarita helicina.
Every tide brings different species of the ocean fauna to temporary imprisonment in this inclosure, so that it is difficult to say what one may not chance to find in this interesting place.