Chapter VIII: Front Matter (8)

The nature of the food is known by the grinders, to the form of which the articulation of the jaws universally corresponds.

To cut flesh, grinders are required as trenchant as a saw and jaws fitted like scissors, having no other motion than a vertical one.

For bruising roots or grains flat-crowned grinders are necessary, and jaws that have a lateral motion; in order that inequalities may always exist on the crown of these teeth, it is also requisite that their substance be composed of parts of unequal hardness, so that one may wear away faster than others.

Hoofed animals are necessarily herbivorous, and have flat-crowned grinders, inasmuch as their feet preclude the possibility of their seizing a living prey.

Animals with unguiculated fingers were susceptible of more variety; their food is of all kinds, and independently of the form of their grinders, they differ greatly from each other in the pliability and delicacy of their fingers. There is one character with respect to this which has immense influence on their dexterity and greatly multiplies its powers; it is the faculty of opposing the thumb to the finger for the purpose of seizing minute objects, constituting what is properly called a hand, a faculty which is carried to its highest perfection in man, in whom the whole anterior extremity is free and capable of prehension.

These various combinations which strictly determine the nature of the different mammalia have given rise to the following orders:

Among the unguiculated animals, the first is Man, who, in addition to privileges of other descriptions, possesses hands at the anterior extremities only, the posterior being designed to support him in an erect position.

In the order next to man, that of the Quadrumana, we find hands at the four extremities.

In another order, that of the Carnivora, the thumb is not free, and can not be opposed to the anterior extremities.

Each of these orders has the three sorts of teeth, grinders, canini, and incisors, or cutting teeth.

In the fourth order, that of the Rodentia, the toes differ but little from those of the Carnivora, but there are no canine teeth, and the incisors are placed in front of the mouth, and adapted to a very peculiar sort of manducation.

Then come those animals whose toes are much cramped and deeply sunk in large nails, which are generally curved; they have no incisors, and in some the canines disappear, while others have none of any description. We comprise them all under the title of Edentata.

This distribution of the unguiculated animals would be perfect and form a very regular series were it not that New Holland has lately furnished us with a little collateral one, consisting of animals with pouches, the different genera of which are connected by a general similarity of organization; some of them, however, in the teeth and nature of their diet corresponding to the Carnivora and others to the Rodentia, and a third to the Edentata.

The hoofed animals are less numerous, and have likewise fewer irregularities.

The Ruminantia, by their cloven foot, the absence of true incisors in their upper jaw, and their four stomachs, form an order that is very distinct.

The remaining hoofed animals may all be united in a single order, which I shall call Pachydermata or Jumenta, the elephant excepted, which might constitute a separate one, and which is remotely connected with that of the Rodentia.

In the last place we find those of the mammalia which have no posterior extremities, whose piscatory form and aquatic mode of life would induce us to form them into a particular class, were it not that in everything else their economy is similar to that in which we have them. These are the hot-blooded fishes of the ancients, or the Cetacea, which, uniting to the vigor of the other mammalia the advantage of being sustained by the watery element, present to our wondering sight the most gigantic of animals.

ZOOLOGICAL ZONES
--SIR RICHARD OWEN

Organic life in its animal form is much more developed, and more variously, in the sea than in its vegetable form.

Observations of marine animals have led to attempts at generalizing the results; and the modes of enunciating these generalizations or laws of geographical distribution are very analogous to those which have been applied to the vegetable kingdom, which is as diversely developed on land as is the animal kingdom in the sea. Certain horizontal areas, or provinces, have been characterized by the entire assemblage of animals and plants constituting their population, of which a considerable proportion is peculiar to each province, and the majority of the species have their areas of maximum development within it.

Of such provinces of marine life, that much-lamented, far-seeing, and genial philosopher, Edward Forbes, has provisionally defined twenty-five.

The same physical conditions are associated with a certain similarity between the animals of different provinces. Where those provinces are proximate, such likeness is due to the identity or close affinity of the species; but where the provinces are remote the resemblance is one of analogy, and species of different genera or families represent each other.

A second mode of expressing the ascertained facts of the geographical distribution of marine animals is by tracts called Homoiozoic Belts, bounded by climatal lines; which are not, however, parallel with lines of latitude, but undulate in subordination to climatal influences of warm or cold oceanic currents, relations of land to water, etc. Of these belts Professor E. Forbes has defined nine: one equatorial, with four to the north and four to the south, which are mutually representative.

But the most interesting form of expression of the distribution of marine life is that which parallels the perpendicular distribution of plants. Edward Forbes, availing himself of the valuable results of a systematic use of the dredge, first showed that marine animals and plants varied according to the depth at which they lived in a manner very analogous to the changes in the forms and species of vegetation observed in the ascent of a tropical mountain. He has expressed these facts by defining five bathymetrical zones, or belts of depth, which he calls: 1. Littoral; 2. Circumlittoral; 3. Median; 4. Infra-median; 5. Abyssal.

The life-forms of these zones vary, of course, according to the nature of the sea bottom; and are modified by those primitive or creative laws that have caused representative species in distant localities under like physical conditions--species related by analogy.

Very much remains to be observed and studied by naturalists in different parts of the globe, under the guidance of the generalizations thus sketched out, to the completion of a perfect theory. But in the progress to this, the results can not fail to be practically most valuable. A shell or a sea-weed, whose relations to depth are thus understood, may afford important information or warning to the navigator. To the geologist the distribution of marine life according to the zones of depth has given the clew to the determination of the depth of the seas in which certain formations have been deposited.

By the light of these laws of geographical distribution we view with quite a new interest the shells, corals, and sea-weeds of our own shores. We trace the regions whence they have been invaded by races not aboriginally belonging to our seas; we obtain indications of irruptions of sea-currents of dates anterior to the present arrangements of land and water. Thus, part of our marine fauna has been traced back to the old Pliocene period, part to the somewhat newer period of the red-crag, part to the still more recent glacial period--all these being anterior to the constitution of the Celtic Province, as it is now displayed.

The class of animals to which the restrictive laws of geographical distribution might seem least applicable is that of birds: their peculiar power of locomotion, associated in numerous species with migratory habits, might seem to render them independent of every influence, save those of climate and of food, which directly affects the conditions of their existence. Yet the long-winged albatross is never met with north of the equator; nor does the condor soar above other mountains than the Andes. The geographical range of its European representative, the strong-winged lammergeyer, is similarly restricted. The Asiatic Phasianidæ and Pavonidæ are represented by turkeys (Meleagris) in America; by the guinea-fowl (Numida Agelastus, Phasidus) in Africa, and by the Megapodiæ or mound birds in Australia. Several genera of finches are peculiar to the Galapagos Islands; the richly and fantastically ornate birds of paradise are restricted to New Guinea and some neighboring isles. Mr. Sclater, who has contributed the latest summary of facts on the distribution of birds, reckons seventeen families as peculiar to America and sixteen families as peculiar to Europe, Asia, and Africa. Some species have a singularly restricted locality, as the red-grouse (Tetrao scoticus) to the British Isles; the owl-parrot (Nestor productus) to Philip Island, a small spot near New Zealand.

When birds have wings too short for flight, we marvel less at their restricted range; and particular genera of brevipennate birds have their peculiar continents and islands. The long and strong-limbed ostrich courses over the whole continent of Africa and conterminous Arabia. The genus of three-toed ostriches (rhea) is similarly restricted to South America. The emeu (Dromaius) has Australia assigned to it. The continent of the cassowary (Casaurius) has been broken up into Sumatra, Java, Banda, and other islands, extending from the southeastern peninsula of Asia to New Guinea. A second species of cassowary has recently been imported to our zoological gardens from the more southern island of New Britain. The singular nocturnal wingless kivi (apteryx) is peculiar to the island of New Zealand.

Other species and genera which seem to be like the apteryx, as it were mocked with feathers and rudiments of wings, have wholly ceased to exist within the memory of man in the islands to which they were respectively restricted. The dodo (Didus ineptus) of the Mauritius, and the solitaire (Pezophops solitaria) are instances.

In New Zealand also there existed, within the memory of the Maori ancestry, huge birds having their nearest affinities to the still existing apteryx of that island, but generically distinct from that and all other known birds. I have proposed the name of Dinornis for this now extinct genus, of which more than a dozen well-defined species have come to my knowledge, all peculiar to New Zealand, and the last discovered the strangest, by reason of the elephantine proportions of its feet. A tridactyle wingless bird of another genus, Æpyornis, second only to the gigantic Dinornis in size, appears to have only recently become extinct--if it be extinct--in the island of Madagascar. The egg of this bird, which may have suggested to the Arabian voyagers, attaining Madagascar from the Red Sea, the idea of the Roc of their romances, would hold the contents of six eggs of the ostrich, sixteen eggs of the cassowary, and one hundred and forty-eight eggs of the common fowl.

Had all the terrestrial animals that now exist diverged from one common centre within the limited period of a few thousand years, it might have been expected that the remoteness of their actual localities from such ideal centre would bear a certain ratio with their respective powers of locomotion. With regard to the class of birds, one might have expected to find that those which were deprived of the power of flight, and were adapted to subsist on the vegetation of a warm or temperate latitude, would still be met with more or less associated together, and least distant from the original centre of dispersion situated in such a latitude. But what is the fact? The species of no one order of birds is more widely dispersed over the earth than the wingless or struthious kind. Assuming that the original centre has been somewhere in the southwestern mountain range of Asia, there is but one of the species of flightless birds whose habitat can be reconciled with the hypothesis. By the neck of land still uniting Asia with Africa, the progeny of the primary pair created or liberated at the hypothetical centre might have traveled to the latter continent, and there have propagated and dispersed themselves southward to the Cape of Good Hope. It is remarkable, however, that the ostrich should not have migrated eastward over the vast plains or steppes which extend along the warmer temperate zone of Asia, or have reached the southern tropical regions; it is in fact scarcely known in the Asiatic continent, being restricted to the Arabian deserts, and being rare even in those parts which are most contiguous to what I have called its proper continent, Africa. If we next consider the locality of the cassowary, we find great difficulty in conceiving how such a bird could have migrated to the islands of Java, the Moluccas, or New Guinea, from the continent of Asia. The cassowary is not web-footed like the swimming birds; for wings it has only a few short and strong quills. How could it have overcome the obstacles which some hundreds of miles of ocean would present to its passage from the continent of Asia to those islands? If the difficulty already be felt to be great in regard to the insular position of the cassowary, it is still greater when we come to apply the hypothesis of dispersion from a single centre to the dodo of the island of Mauritius, or the solitaire of the island of Rodriguez. How, again, could the emeu have overcome the natural obstacles to the migration of a wingless terrestrial bird from Asia to Australia? and why should not the great continent of Asia have offered in its fertile plains a locality suited to its existence, if it ever at any period had existed on that continent? A bird of the nature of the emeu was hardly less likely to have escaped the notice of scientific travelers than the ostrich itself; but, save in the Arabian deserts, the ostrich has not been found in any part of Asia, and no other species of wingless birds has ever been met with on that continent; the evidence in regard to such large and conspicuous birds is conclusive to that fact. Again, in order that the rhea, or three-toed ostrich, should reach South America by traveling along that element on which alone it is organized and adapted to make progress, it must, on the hypothesis of dispersion from a single Asiatic centre, have traveled northward into the inhospitable wilds of Siberia; it must have braved and overcome the severer regions of the Arctic zone; it must have maintained its life with strength adequate to the extraordinary power of walking and running more than a thousand miles of land or frozen ocean utterly devoid of the vegetables that now constitute its food before it could gain the northern division of America, to the southern division of which it is at present and seems ever to have been confined. The migration in this case could not have been gradual and accomplished by successive generations. No individual of the large vegetable-feeding wingless bird that now subsists in South America could have maintained its existence, much less hatched its eggs, in Arctic latitudes, where the food of the species is wholly absent. If we are still to apply the current hypothesis to this problem in natural history, we must suppose that the pair or pairs of the rhea that started from the highest temperate zone in Asia capable of maintaining their life must have also been the same individuals which began to propagate their kind when they reached the corresponding temperate latitude of America. But no individuals of the rhea have remained in the prairies or in any part of North America--they are limited to the middle and southern division of the South American continent. And now, finally, consider the abode of the little apteryx at the Antipodes, in the comparatively small insulated patch of dry land formed by New Zealand. Let us call to mind its very restricted means of migration--the wings reduced to the minutest rudiments, the feet webless like the common fowls, its power of swimming as feeble! How could it ever have traversed six hundred miles of sea that separate it from the nearest land intervening between New Zealand and Asia? How pass from the southern extremity of that continent to the nearest island of the Indian Archipelago, and so from member to member of that group to Australia--and yet leave no trace behind of such migration by the arrest of any descendants of the migratory generations in Asia itself, or in any island between Asia and New Zealand?

If these facts are inexplicable on the hypothesis of the dispersion of the species of the air-breathing animals from a single Asiatic centre, we must next endeavor to collect analogous facts and classify them, and so try to explain intelligibly, that is agreeably with the facts, the true law or cause of the actual geographical distribution of animals.

The laws of geographical distribution, as affecting mammalian life, have been reduced to great exactness by observations continued since the time of Buffon, who first began to generalize about a century ago in that way, noting the peculiarities of the species of South American animals. The most important extension of this branch of zoology has been due to recent researches and discoveries of extinct species of the class Mammalia; and it is chiefly in relation to the modifications of zoological ideas produced by palæontology that a few brief remarks will here be made.

The Quadrumana, or order of apes, monkeys, and lemurs, consist of three chief divisions--Catarhines, Platyrhines, and Strepsirhines. The first family is peculiar to the Old World; the second to South America; the third has the majority of its species and its chief genus (Lemur) exclusively in Madagascar. Out of twenty-six known species of Lemuridæ, only six are Asiatic and three are African.

The Catarhine monkeys include the Macaques, most of which are Asiatic, a few are African and one European; the Cercopitheques, most of which are African and a few Asiatic; and other genera which characterize one or other continent exclusively. Thus the true baboons (Papio) are African, as are the thumbless monkeys (Colobus) and the chimpanzees (Troglodytes). The Semnopithecus, gibbons, and orangs are peculiarly Asiatic. Palæontology has shown that a macaque, a gibbon, and an orang existed during the older Tertiary times in Europe, and that Semnopithecus existed in Miocene times in India. But all the fossil remains of Quadrumana in the Old World belong to the family Catarhina, which is still exclusively confined to that great division of dry land. The tailless macaque (Innus silvanus) of Gibraltar may have existed in that part of the Old World before Europe was separated by the Straits of Gibraltar from Africa. Fossil remains of Quadrumana have been discovered in South America; they indicate Platyrhine forms: a species, for example, allied to the howlers (Mycetes), but larger than any now known to exist, has left its remains in Brazil.

While adverting to the geographical distribution of Quadrumana, I would contrast the peculiarly limited range of the orangs and chimpanzees with the cosmopolitan powers of mankind. The two species of orang (Pithecus) are confined to Borneo and Sumatra; the two species of chimpanzee (Troglodytes) are limited to an intertropical tract of the western part of Africa. They appear to be inexorably bound by climatal influences regulating the assemblage of certain trees and the production of certain fruits. With all our care, in regard to choice of food, clothing, and contrivances for artificially maintaining the chief physical conditions of their existence, the healthiest specimens of orang or chimpanzee, brought over in the vigor of youth, perish within a period never exceeding three years, and usually much shorter in England. By what metamorphoses, may we ask, has the alleged humanized chimpanzee or orang been brought to endure all climates? The advocates of transmutation have failed to explain them. Certain it is that those physical differences in cerebral, dental, and osteological structure which place, in my estimate of them, the genus Homo in a distinct group of the mammalian class, zoologically of higher value than the order, are associated with equally contrasted powers of endurance of different climates, whereby man has become a denizen of every part of the globe from the Torrid to the Arctic zones.

Climate rigidly limits the range of the Quadrumana latitudinally; creational and geographical causes limit their range in longitude. Distinct genera represent each other in the same latitudes of the New and Old Worlds; and also, in a great degree, in Africa and Asia. But the development of an orang out of a chimpanzee, or reciprocally, is physiologically inconceivable.

The order Ruminantia is principally represented by Old World species, of which 162 have been defined, while only 24 species have been discovered in the New World, and none in Australia, New Guinea, New Zealand, or the Polynesian Isles.

The camelopard is now peculiar to Africa; the musk-deer to Africa and Asia; out of fifty defined species of antelope, only one is known in America, and none in the central and southern divisions of the New World. The bison of North America is distinct from the bison of Europe. The musk-ox alone, peculiar for its limitation, to high northern latitudes, roams over the Arctic coasts of both Asia and America. The deer tribe are more widely distributed. The camels and dromedaries of the Old World are represented by the llamas and vicunas of the New. As, in regard to a former (Tertiary) zoological period, the fossil Camilidæ of Asia are of the genus Camilus, so those of America are of the genus Auchenia. This geographical restriction ruled prior to any evidence of man’s existence.

Palæontology has expanded our knowledge of the range of the giraffe: during Miocene or old Pliocene periods, species of Camelopardalis roamed in Asia and Europe. Passing to the non-ruminant Artiodactyles, geology has also taught us that the hippopotamus was not always confined, as now, to African rivers, but bathed, during Pliocene times, in those of Asia and Europe. But no evidence has yet been had that the giraffe or hippopotamus were ever other than Old World forms of Ungulata.

With respect to the hog tribe, we find that the true swine (Sus) of the Old World are represented by peccaries (Dicotyles) in the New; and geology has recently shown that Tertiary species of Dicotyles existed in North as well as South America. But no true Sus has been found fossil in either division of the New World, nor have the Dicotyles been found fossil in the Old World of the geographer. One of the earliest forms of the European rhinoceros was devoid of the nasal weapon.

Geology gives a wider range to the horse and elephant kinds than was cognizant to the student of living species only. The existing Equidæ and Elephantidæ properly belong, or are limited, to the Old World; and the elephants to Asia and Africa, the species of the two continents being quite distinct. The horse, as Buffon remarked, carried terror to the eye of the indigenous Americans, viewing the animal for the first time, as it proudly bore their Spanish conqueror. But a species of Equus coexisted with the Megatherium and Megalonyx in both South and North America, and perished apparently with them, before the human period. Elephants are dependent chiefly upon trees for food. One species now finds conditions of existence in the rich forests of tropical Asia; and a second species in those of tropical Africa. Why, we may ask, should not a third be living at the expense of the still more luxuriant vegetation watered by the Orinoco, the Essequibo, the Amazon, and La Plata, in tropical America? Geology tells us that at least two kinds of elephant (Mastodon Andium and Mastodon Humboldtii) formerly did derive their subsistence, along with the great Megatheroid beasts, from that abundant source. Nay, more; at least two kinds of elephant (Mastodon ohioticus and Elephas texianus) existed in the warm and temperate latitudes of North America. Twice as many species of mastodon and elephant, distinct from all the others, roamed in Pliocene times in the same latitude of Europe. At a later or Pleistocene period, a huge elephant, clothed with wool and hair, obtained its food from hardy trees, such as now grow in the 65th degree of north latitude; and abundant remains of this Elephas primigenius (as it has been prematurely called, since it was the last of the British elephants) have been found in temperate and high northern latitudes in Europe, Asia, and America. This, like other Arctic animals, was peculiar in its family for its longitudinal range. The musk buffalo was its contemporary in England and Europe, and still lingers in the northernmost parts of America.

I have received evidences of elephantine species from China and Australia, proving the proboscidian pachyderms to have been the most cosmopolitan of hoofed herbivorous quadrupeds. Geology extends the geographical range of the sloths and armadillos from South to North America; but the deductions from recent rich discoveries of huge terrestrial forms of sloth, of gigantic armadillos, and large anteaters go to establish the fact that these peculiar features of the order Bruta have ever been, as they are now, peculiar to America; that several genera, including the larger species, have perished; and that the range of their still existing diminutive representatives has been reduced to the southern division of the New World.

Australia, which in extent of dry land merits to be regarded as a fifth continent, has a more restricted and peculiar character of aboriginal mammalian population than South America. It is emphatically the “province” of those quadrupeds the females of which are provided with a pouch for the transport and protection of their prematurely formed young.

One genus of Marsupialia (Didelphys or opossums, properly so called) is peculiar to America, and is there the sole representative of the order. A small kangaroo, and a few phalangers, exist in islands that link the Malayan Archipelago with the Australian world. All the other marsupial genera are found in Australasia, comprising New Guinea, Australia, and Tasmania. The largest and most destructive of carnivorous marsupials are peculiar to Tasmania.

The sum of all the evidence from the fossil world in Australia proves its mammalian population to have been essentially the same in Pleistocene, if not Pliocene, times as now; only represented, as the Edentate mammals in South America were then represented, by more numerous genera, and much more gigantic species than now exist.

In the Miocene and Eocene tertiary deposits, marsupial fossils of the American genus Didelphys have been found, both in France and England; and they are associated with tapirs like that of America. In a more ancient geological period, remains of marsupials, some insectivorous, others with teeth, have been found in the upper Oolite.

Thus it would seem that the deeper we penetrate the earth, or, in other words, the further we recede in time, the more completely we are absolved from the present laws of geographical distribution.

GEOGRAPHICAL DISTRIBUTION OF ANIMALS
--WILLIAM HUGHES

The great division of the animal kingdom recognized by naturalists is that into vertebrate and invertebrate animals. Vertebrated animals are those which possess a spinal bone, to which are attached ribs, constituting the framework of the entire body. All animals of this division have red blood. The vertebrate animals comprehend fishes, reptiles, birds, and mammalia. This last term is inclusive of all animals that suckle their young, man among the number.

The class mammalia comprehends the following orders: 1. Carnivora (_flesh-eating_, as the lion, tiger, etc.); 2. Ruminantia (_animals that chew the cud_, as the camel, ox, sheep, and others); 3. Pachydermata (_thick-skinned_, as the elephant, horse, etc.); 4. Rodentia (_gnawing_, as the beaver, squirrel, mice, etc.); 5. Edentata (_toothless_, as the ant-eater and armadillo); 6. Quadrumma (_four-handed_, as the ape and monkey tribe); 7. Cherioptera (having _winged arms_, as bats); 8. Marsupialia (_pouched_, as the kangaroo and opossum); 9. Cetaceæ (whales, dolphins, and the various seals). The last-mentioned of these divisions includes members (and those the largest) of a tribe assigned in popular language to a distinct division of the animal world--fishes. But the whale and other creatures of its order possess the distinguishing attribute of the mammalia--that is, they afford their nutriment from the breast.

The animals belonging to the ruminating and pachydermatous orders are further distinguished as ungulata, or hoofed, from the well-known characteristic of their extremities. The domesticated animals that are used as food by man are almost exclusively derived from this class. The animals included within the other orders of mammalia are designated as unguiculata, from their extremities terminating in claws, or nails.

The invertebrate animals, or those which have no spinal bone, all have white blood. They are scientifically divided into molluscous animals, in which the muscles are attached to the skin, with or without the protection of a shell--such as snails and slugs; articulated animals, in which the covering of the body is divided into rings or segments, to the interior of which the muscles are attached--comprehending all insects and worms; and radiated animals, in which the organs of motion or sensation radiate from a common centre--such as star-fish.

The opposite sides of a hill-range, even in cases where the climate is nearly identical, and the passage from one slope to the other easy, will often exhibit different conditions of animal life. Isothermal lines mark--with hardly less precision in the case of animals than of plants--the range of particular families and species, in the direction of latitude and elevation alike. The fact that such is the case testifies strongly to the force of those instincts with which all animals are endowed, and by which their habits are regulated. The powers of locomotion possessed by animals might at first sight seem calculated to favor a wider extension of geographical range than belongs to vegetables, and in the well-known instances of migratory species (of which the swallow and other birds are familiar examples) such is undoubtedly the case. But even these migrations are confined within a well-defined range, determined by conditions of climate, and facility of obtaining the necessary food. Birds in general are separated, as markedly as quadrupeds, in respect of their habitat, or geographical range. This is equally true, indeed, in regard to every one of the great classes into which the animal world is divided. Each zone of the ocean, both in latitude and in the direction of depth, has its proper forms of life.

To take an instance from land animals, the elephant is confined by natural instinct within the belt of the warm latitudes, and not more so by the high temperature which such latitudes alone enjoy than by the limitation of its necessary food to the regions which are its proper home. Nowhere else but within or near the tropics is there found the luxuriant abundance of forest vegetation which the elephant requires to make sustenance upon. The reindeer, on the other hand, is as characteristically an inhabitant of polar latitudes, and perishes if brought within the continued influence of a warmer temperature than that of his native region. The ibex and the chamois, with some other animals of the goat tribe, frequent only the highest and least accessible portions of the mountain region, while various members of the deer kind range over the lower elevations and the plains below. Of birds, the condor, or great vulture of the Andes, confines his range within the region of the highest peaks of the mountain region, as his European congener--the lammergeyer, or vulture of the Alps--does in another part of the globe. In the mountainous portions of Great Britain, the eagles which (notwithstanding the keen pursuit of the sportsman) frequent the scarcely accessible crags that surround Loch Maree and other secluded localities of the Highlands, furnish a similar instance. Again, the shark is the well-known scourge of the warmer belt of ocean, while the same zone of sea constitutes--from its high temperature--a region through which the whale never passes.

It is, besides, equally true of the animal as of the vegetable kingdom, that every region of the globe has its own proper inhabitants, different in species, for the most part, from those of other regions. The animal life of the Old World is markedly different from that of the New World in correspondent parallels, and under conditions of climate which are in all important regards analogous. Even when the genera, or families, are the same, the species are in nearly all cases distinct. In yet higher measure, the animal life of Australia differs from that of other divisions of the globe. Whole orders of the animal world are wanting in Australian zoology, while the vast majority of its animals belong to a division which is altogether unrepresented in the continents of the Old World--that is, the marsupial tribe. The difference is less strongly marked in the case of the adjacent continents of the Northern Hemisphere than in the instances of the lands lying south of the equator.

The natural distribution of animals has been importantly modified by human agency. This is especially the case in regard to those divisions of the mammalia which comprehend the domestic quadrupeds--the horse, dog, ox, sheep, and others. Man has carried these animals with him in his migrations from one region to another, and has thus introduced new species (and even genera) into lands where they were previously unknown. The horse, the ox, and the common sheep, were unknown in the New World prior to the Spanish discoveries of the Fifteenth and Sixteenth Centuries, but speedily became naturalized there, and, in the case of the two first-named, have long since reverted to a condition of nature. Wild horses roam by thousands over the savannas and pampas of the western world. Within a much more recent period, the domestic cattle of Europe have been introduced into the Australian continent, and have multiplied there to an extraordinary degree. Efforts are now making to introduce into Australia both the camel of the Old World and the llama of South America. The hare and the rabbit of Britain have become naturalized in the more southwardly of the Australian colonies. Similar efforts are at the present time directed to the naturalization in the Australian rivers of the salmon and other fish that belong to the streams and estuaries of Europe. What has been accomplished, in these and many similar cases, by the direct efforts of man, has resulted, in the case of many of the smaller animals, from his involuntary agency, or from accidental causes. The vessel which conveys a cargo of native produce from one region to a foreign shore has often carried with it the germs of life (vegetable as well as animal), besides, in numerous instances, the smaller members themselves of the animal world. The insects that were originally confined to one region have thus become distributed over wide areas of the globe.

A few other of the more obvious differences between the native zoology of the Old and New Worlds may be adverted to with advantage. Among carnivorous quadrupeds, the lion, tiger, leopard, panther, and hyena are confined to the eastern half of the globe. In the New World, the puma and the jaguar take respectively the places of the lion and tiger of the Asiatic continent. Of the ruminants, the camel, the giraffe, and the numerous antelopes are only found within the Old World. Of the pachydermata, the elephant, the rhinoceros, the hippopotamus, the horse, the zebra, and the ass are unknown to the native zoology of the lands lying west of the Atlantic. The elephant, and also the rhinoceros, belong to Asia and Africa (the species being different in the case of either continent), the hippopotamus is African only: the zebra (with its kindred species, the quagga) is also peculiar to Africa. Both the horse and the ass probably came originally from Asia. Of the Quadrumana, which are numerously represented in the zoology of either hemisphere, the species (and, in most cases, the genera) are distinct. Again, the opossums of the New World belong to an order (the marsupial) which is altogether unrepresented in the three continents of the Old World, but which exhibits its fullest development in the Australian division of the globe. Numerous other instances might be adduced, but these will suffice. They serve to show that, in the case of animals as of plants, particular regions constitute centres of particular forms of life, which thence spread, within certain limits, around, still leaving to each such region its strongly marked and typical characteristics in such regards.

Europe exhibits, in its indigenous zoology, a character less marked and distinctive than belongs to other divisions of the globe. This is in some degree the result of its dense population, and the consequent diminution in the number of wild species, but in a more special manner results from its conditions of geographical form and position. Europe is less a continent in itself than an outlying portion of the vast and unbroken mass of the Asiatic continent. No strongly marked feature intervenes between the plains of eastern Europe and those of northern Asia, and within the continuous range of land that extends, under the same parallels, from the Baltic Sea eastward to the waters of the Pacific Ocean, the animal life exhibits for the most part identity of species and genera. The differences between them, in a vast number of instances, are merely varieties. Many of the fur-bearing animals are common to all the lands that lie within the Arctic circle, as many as twenty-seven species being native to Europe, Asia, and North America alike.

The vast population of Europe has necessitated the rearing of the domestic quadrupeds in vast numbers, and has been accompanied, in numerous instances, by the extermination of the wild denizens of the forest. It would seem from a passage in Herodotus (book vii, 125) that the lion once frequented the woods of Macedonia. The wild boar, bear, and the wolf were formerly natives of the British Islands, and the last named animal has only been exterminated from within their limits during the last hundred and fifty years. The beaver, long since banished, was once common on the banks of the Welsh streams. The fox is only preserved by artificial means, and for the purposes of the chase. The wildcat, now rarely seen, and that only in the remoter portions of the Scotch Highlands, was formerly common within the English forests. The bustard, a bird now rarely seen, was once met with in huge flights on the plains of Norfolk and Suffolk, while huge fen-eagles frequented the marshy flats of the adjacent country.

1, Cephalaspis; 2, Pterichthys; 3, Coccocosteus; 4, Diplacanthus; 5, Holoptychius; 6. Osteolepis; 7, 12, 20, Gasteropods; 8, Crinoid; 9, Eurypterus; 10, 13, 15, 18, 19, Trilobites; 14, 16, 17, 23, Cephalopods (Ammonites); 21, 22, Spirifers]

These are but few instances of the way in which human agency modifies the distribution of animal life. On the continent, the extermination of a particular species is of course more difficult; in numerous cases is perhaps altogether impossible. The wolf inhabits the forests of continental Europe, from the high tracts that adjoin the Alps and the Pyrenees northward to the shores of the Baltic and White Seas. The wild boar and the bear (three species of the latter--the brown and the black in the wooded regions of the south, the white polar bear in the extreme north) are still met with. The urus or wild ox of the Lithuanian forests, regarded by naturalists as the progenitor of our common domestic cattle, is even yet found to the eastward of the Baltic.

Europe, however, has no one of the great families of mammalia that can be looked on as peculiarly its own, or, in other words, as giving it a distinctive zoology--like the antelopes of Southern and Western Asia, the numerous pachyderms of the African continent, the llama tribe of the New World, or the marsupials of Australia. Of the total number of European mammalia, not exceeding a hundred and eighty, only fifty-eight are peculiar to this continent, and none of the larger quadrupeds is included among them.

The domesticated animals that are so numerously reared in every part of Europe have probably been, in most cases, derived from indigenous species. The urus or wild ox has been the parent of the common ox, and the wild boar of the domestic pig; the goat, and, in the extreme north, the reindeer, are also native to the European soil. The moufflon of Sardinia was perhaps the ancestor of at least some of our breeds of sheep.

The birds of Europe display a greater number and variety of species than its land animals. This is especially the case in regard to the family of aquatic birds--always most numerous in the higher latitudes. More than thirty species of the duck tribe alone belong to Northern Europe, some of them being common to the corresponding latitudes of Asia and the New World. The stork and the crane (both of migratory habits) belong to the maritime regions of Western Europe; the pelican, the spoonbill, and the scarlet flamingo, to the shores of the Mediterranean.

Europe has fewer species (as well as fewer individuals) of the reptile kind than either of the other divisions of the globe--a happy exemption, which is due to its temperate climate. The only venomous serpents found in Europe are three species of viper, all of them confined to its southern shores: the common viper of middle and Northern Europe is innocuous. Lizards are common in the south, as many as sixty-three species being enumerated.

The waters of Europe exhibit a rich variety of fish, a vast number of them useful as to the food of man. Each of its inland seas has its own peculiar tribes, the Mediterranean basin displaying the richest diversity. Among the inhabitants of the Mediterranean are several sharks, swordfish, dolphins, and six species of tunny--the last-mentioned the largest of edible fish. The anchovy is peculiar to the Mediterranean. The seas that lie around the British Islands abound in the gregarious tribes of edible fish, as the cod, turbot, mackerel, herring, pilchard, and many others. The stromming of the Baltic is of like utility. The salmon frequents the estuaries and river-mouths throughout the coast-line of Western Europe to the northward of the Bay of Biscay, becoming more numerous as higher latitudes are reached.

The generally temperate climate of Europe secures it, for the most part, an exemption from the dense swarms of insect-life that belong to warmer latitudes. Yet between eight or nine thousand species are enumerated as native to the British Islands alone. The common honey-bee is distributed all over southern and Central Europe, and is probably indigenous. The locust is only an occasional visitor to its shores, and belongs to the other side of the Mediterranean. The silkworm was introduced from China toward the close of the Fifth Century of our era.

Asia is rich in variety of animal life, and especially so as regards the class mammalia, all the orders of which but two (the marsupials and the edentata) are represented in its zoology. Of domesticated quadrupeds, the camel, ox, goat, and sheep, among the ruminants, with the horse, the ass, and the elephant, among pachyderms, are natives of Asia. The camel, of which there are several species, all natives of this continent, ranges from the shores of the Indian Ocean and Red Sea as far north as Lake Baikal. The reindeer and elk frequent the Siberian and Mongolian plains, migrating from the former locality southward with the approach of winter. Numerous varieties of the ox tribe (including the common ox, aurochs, buffalo, and yak) are reared by the Tartar nations who inhabit the upland plains of the interior. The antelope and deer tribe, of which there are a vast number of species, belong to the western and southwestern regions of the continent. The plains of Turkestan, to the eastward of the Caspian, are perhaps the original country of the horse. The wild ass is indigenous to Western Asia. The elephant is not found to the west of India, nor to the north of the Himalaya Mountains; it belongs only to the two Indian peninsulas, with Ceylon, and some of the smaller islands of the Malay archipelago.

Among Asiatic carnivora are the lion, tiger, leopard, panther, and ounce, of the cat genus: the wolf, hyena, and jackal, of the dog tribe. Two species of bear are native to the Himalaya region (the snow-bear, and the black-bear) and the polar bear belongs to the Arctic coasts of the continent. The lion of Asia is now restricted to the region which extends from the banks of the Euphrates and Tigris to the western coasts of the Indian peninsula, including the deserts of Mesopotamia, Persia, and Hindostan. The tiger has a more extensive range, and inhabits all the middle and southeastern divisions of the continent. The hyena, and also the jackal, belong to the western half of Southern Asia; the wolf frequents the northern and western plains, and is found in a range of country extending from Siberia, through Turkestan, to the shores of the Mediterranean. The dog and the fox are common all over the continent, and present numerous varieties; in Kamtchatka and some parts of Siberia, the former animal is used as a beast of burden, and is trained to draw the sledges over the vast plains of ice and snow.

Numerous fur-bearing animals occur in Siberia, including the bear, glutton, badger, wolf, fox, lynx, pole-cat, weasel, ermine, marten, otter, sable, squirrel, beaver, hare, and the reindeer: many of these belong also to the northern regions of Europe. The quadrumana are found in the south and southeast of the continent and the islands of the Malay archipelago; the largest and most remarkable among them--the orang-outang--is restricted to the Malayan peninsula and the islands of Borneo and Sumatra. The gibbons (or long-armed apes) belong exclusively to Asia, and abound in its southeastern parts. Bats are more numerous in the islands of the Asiatic archipelago than on the continent.

Asia is less rich in variety of birds than in quadrupeds, but (with the exception of the turkey, which is a native of the New World, and of the guinea-fowl, which is African) all our domestic poultry came originally from this division of the globe. Among its birds of prey are eagles, vultures, falcons, owls, and hawks; but although individually abundant, the species of these are not numerous. Song-birds are numerous in western Asia, but are comparatively scarce in the eastern division of the continent, where, however (especially among the islands of the Malay archipelago and in China), birds of beautiful plumage abound. The peacock is a native of India, the golden pheasants belong to China, and the birds of paradise to New Guinea and the adjacent islands.

Reptiles are less numerous in Asia than in some other parts of the globe, but are sufficiently common in the southeastern parts of the continent and the adjacent islands. The python (analogous to the boa-constrictor of the New World) lurks in the morasses and swamps of the East Indian islands; the cobras, with several other kinds of venomous serpents, are found in the peninsulas of Eastern and Western India. Both sea and fresh-water snakes are numerous. Among insects, the locust is abundant in Western Asia, and commits the most dreadful ravages among the crops in Syria, Persia, and Arabia.

Africa is yet richer than Asia in regard to the animal kingdom. Of the total number of mammalia, more than a fourth occur in this division of the Old World, and fewer than a sixth of the number are common to Africa with either of the other continents. It is in the carnivora, ruminants, pachyderms, and quadrumana, that African zoology is more especially rich. Only one order, the marsupial, is unrepresented in it. Nor is the varied abundance of animal life in this region of the globe confined to species; the development of individual life within its vast and almost boundless solitudes is yet more characteristic.

Among African beasts of prey are the lion, panther, leopard, wolf, fox, hyena, and jackal. Three varieties of the lion occur--that of Northern Africa, of the countries on the Senegal, and of the extreme south, toward the Orange River. There are two hyenas--one, the spotted hyena, a native of Southern Africa; the other, the striped hyena, indigenous to the more northerly parts of the continent, and extending its range from Abyssinia and Barbary into Western Asia. The wolf and the jackal belong to Northern Africa.

Of ruminants, there are no less than sixty species of the antelope kind, which is especially abundant in Southern Africa. The camelopard or giraffe is peculiar to this continent, and ranges from the banks of the Gariep to the southern borders of the Sahara, but is not found upon the western coasts. Several species of buffalo occur in a wild state, and are most abundant within the outlying districts of the Cape Colony. Sheep and goats abound in most parts of Africa, but are probably not indigenous; both in Barbary and near the Cape of Good Hope--at the opposite extremities of the continent--are found sheep with broad, fat tails, so large as sometimes to weigh from ten to thirty pounds. The camel of Africa is found all over its northern and central regions.

Of the Pachydermata, or thick-skinned animals, the most characteristic are the elephant, rhinoceros, and hippopotamus. The elephant is found dispersed, in immense herds of from one to three hundred, all over the wooded regions of Central and Southern Africa, and the rhinoceros frequents principally the same localities. The ivory supplied by the tusks of the former is one of the most valuable native products of this quarter of the globe. The rhinoceros is valued chiefly for its hide, which is made into shields and harness. The hippopotamus is found in the upper part of the Nile valley, and in all the lakes and rivers to the southward of the Great Desert--including the Senegal, the Gambia, the Congo, and the Gariep. This animal is peculiar to Africa; its teeth consist of the finest ivory, for the sake of which it is hunted by the settlers of the Cape. All three of these animals are used as food by the native races of the South African interior.

The wild boar is found in some parts of Africa: the zebra, dow, and quagga (all peculiar to this continent) abound in its central and southern regions, particularly in the arid plains in the neighborhood of the Orange River. Of the African Quadrumana, monkeys, baboons, apes, and lemurs abound in the forests throughout every part of the continent.

The chimpanzee of the western coasts (from the neighborhood of Sierra Leone to the 10th parallel of S. latitude) makes nearer approach to the human form than the orang-outang of Southeastern Asia, but is surpassed in this respect by the gorilla, one of the largest of the ape tribe, which inhabits the forests in the neighborhood of the Gaboon River (0° 30′ N. lat.).

Bats are numerous in Africa, and most of the species inhabiting this continent are peculiar to it. The Rodentia are also for the most part of peculiar species; among them are hares, rabbits, jerboas, squirrels, rats, and mice.

Among birds, the ostrich is confined to Africa, but ranges from its southern extremity to the northern borders of the Great Desert. Its feathers form a highly valued article of traffic, and the bird is domesticated in many parts of Africa for the sake of procuring these free from injury. The vulture (of which two species occur--one in Northern Africa and the other in the neighborhood of the Cape) serves here, as elsewhere, to preserve the air from impurity, by feeding on the carcasses of animals, and divides with the hyena the office of scavenger. The owl, falcon, and eagle are also enumerated among the African birds of prey. Of gallinaceous birds Africa possesses only the guinea-fowl; but the domestic poultry are numerously reared, though not indigenous. The woods of tropical Africa abound in numberless varieties of parrots and paroquets, besides many other birds of bright and gaudy plumage--as the beautiful sun-birds (which inhabit the western coasts, and are scarcely larger than the humming-birds of America), together with the golden-colored orioles, crested hoopoes, bee-eaters, and others. The honey-suckers, which abound in the neighborhood of the Cape of Good Hope, feed entirely upon the nectar or saccharine juice of the proteas and similar plants. The sun-birds also occur in Southern Africa, and rival those of India and the Gambia in the brilliancy of their colors.