We shall best understand the wonderfully complex system of a.n.a.logies developed by that theory, if we start from the part of the kingdom in which they were first traced,--namely, the cla.s.s aves, or birds.
This gives for its five orders,--incessores, (perching birds,) raptores, (birds of prey,) natatores, (swimming birds,) grallatores, (waders,) rasores, (sc.r.a.pers.) In these orders our naturalists discerned distinct organic characters, of different degrees of perfectness, the first being the most perfect with regard to the general character of the cla.s.s, and therefore the best representative of that cla.s.s; whence it was called the TYPICAL order. The second was found to be inferior, or rather to have a less perfect balance of qualities; hence it was designated the SUB-TYPICAL. In this are comprehended the chief noxious and destructive animals of the circle to which it belongs. The other three groups were called aberrant, as exhibiting a much wider departure from the typical standard, although the last of the three is observed to make a certain recovery, and join on to the typical group, so as to complete the circle. The first of the aberrant groups (natatores) is remarkable for making the water the theatre of its existence, and the birds composing it are in general of comparatively large bulk. The second (grallatores) are long-limbed and long-billed, that they may wade and pick up their subsistence in the shallows and marshes in which they chiefly live.
The third (rasores) are distinguished by strong feet, for walking or running on the ground, and for sc.r.a.ping in it for their food; also by wings designed to scarcely raise them off the earth and, farther, by a general domesticity of character and usefulness to man.
Now the most remarkable circ.u.mstance is, that these organic characters, habits, and moral properties, were found to be traceable more or less distinctly in the corresponding portions of every other group, even of those belonging to distant subdivisions of the animal kingdom, as, for instance, the insects. The incessores (typical order of aves) being reduced to its const.i.tuent circles or tribes, it was found that these strictly represented the five orders. In the conirostres are the perfections which belong to the incessores as an order, with the conspicuous external feature of a comparatively small notch in their bills; in the dentirostres, the notch is strong and toothlike, (hence the name of the tribe) a.s.similating them to the raptores; the fissirostres come into a.n.a.logy with the natatores in the slight development of their feet and their great powers of flight; the tenuirostres have the small mouths and long soft bills of the grallatores. Finally, the scansores resemble the rasores in their superior intelligence and docility, and in their having strong limbs and a bill entire at the tip. This parity of qualities becomes clearer when placed in a tabular form:-
Orders of Birds. Characters. Tribes of Incessores.
Incessores --Most perfect of their circle; Conirostres.
notch of bill small Raptores --Notch of bill like a tooth Dentirostres.
Natatores --Slightly developed feet; Fissirostres.
strong flight Grallatores--Small mouths; long soft bills Tenuirostres.
Rasores --Strong feet, short wings; Scansores.
docile and domestic
Some comprehensive terms are much wanted to describe these five characters, so curiously repeated throughout the whole of the animal, and probably also the vegetable kingdom. Meanwhile, Mr. Swainson calls them typical, sub-typical, natatorial, suctorial, {242} and rasorial. Some of his ill.u.s.trations of the principle are exceedingly interesting. He shews that the leading animal of a typical circle usually has a combination of properties concentrated in itself, without any of these preponderating remarkably over others. The sub- typical circles, he says, "do not comprise the largest individuals in bulk, but always those which are the most powerfully armed, either for inflicting injury on their own cla.s.s, for exciting terror, producing injury, or creating annoyance to man. Their dispositions are often sanguinary, since the forms most conspicuous among them live by rapine, and subsist on the blood of other animals. They are, in short, symbolically types of EVIL." This symbolical character is most conspicuous about the centre of the series of gradations:-
Kingdom . . . Annulosa.
Sub-kingdom . . . Reptilia.
Cla.s.s (Mammalia) . . . Ferae.
(Aves) . . . Raptores.
In the annulosa it is not distinct, although we must also remember that insects do produce enormous ravages and annoyance in many parts of the earth. In the reptilia it is more distinct, since to this cla.s.s belong the ophidia, (serpents,) an order peculiarly noxious.
It comes to a kind of climax in the ferae and raptores, which fulfil the function of butchers among land animals. As we descend through tribes, families, genera, species, it becomes fainter and fainter, but never altogether vanishes. In the dentirostres, for instance, we have in a subdued form the hooked bill and predaceous character of the raptores; to this tribe belongs the family of the shrikes, so deadly to all the lesser field birds. In the genus bos, we have, in the sub-typical group, the bison, "wild, revengeful, and shewing an innate detestation of man." In equus, we have, in the same situation, the zebra, which actually shews the stripes of the tiger, and is as remarkable for its wildness as its congeners, the horse and a.s.s, are for their docility and usefulness. To quote again from Mr.
Swainson, "the singular threatening aspect which the caterpillars of the sphinx moth a.s.sume on being disturbed, is a remarkable modification of the terrific or evil nature which is impressed in one form or another, palpable or remote, upon all sub-typical groups; for this division of the lepidopterous order is precisely of this denomination. In the pre-eminent type of this order of insects, the b.u.t.terflies, (papilionides,) our a.s.sociations little prepare us for expecting any trace of the evil principle; but here, too, there is a sub-typical division. These," says our naturalist, "are distinguished by their caterpillars being armed with formidable spines or p.r.i.c.kles, which in general are possessed of some highly acrimonious or poisonous quality, capable of injuring those who touch them. It is only," continues Mr. Swainson, "when extensive researches bring to light a uniformity of results, that we can venture to believe they are so universal as to deserve being ranked as primary laws. Thus, when a celebrated entomologist denounced as impure the black and lurid beetles forming the saprophagous petalocera of Mr. Macleay, a tribe living only upon putrid vegetable matter, and hiding themselves in their disgusting food, or in dark hollows of the earth, neither of these celebrated men suspected the absolute fact, elicited from our a.n.a.logies of this group, that this very tribe const.i.tuted the sub-typical group of one of the primary divisions of coleopterous insects: nor had they any suspicion that, by the filthy habits and repulsive forms of these beetles, nature had intended that they should be types or emblems of hundreds of other groups, distinguished by peculiarities equally indicative of evil.
On the other hand, the thalerophagous petalocera, forming the typical group of the same division, present us with all the perfections and habits belonging to their kind. These families of beetles live only upon fresh vegetables; they are diurnal, and sport in the glare of day, pure in their food, elegant in their shapes, and beautiful in their colours." {246}
The third type, (first of the three aberrant,) called by Mr.
Swainson, the natatorial, or aquatic, are chiefly remarkable for their bulk, the disproportionate size of the head, and the absence, or slight development of the feet. They partake of the predaceous and destructive character of the adjoining sub-typical group, and the means of their predacity are generally found in the mouth alone. In the primary division of the animal kingdom, we find the type in the radiata, not one of which lives out of water. In the vertebrata, it is in the fishes. In both of these, feet are totally wanting.
Descending to the cla.s.s mammalia, we have this type in the cetacea, which present a comparatively slight development of limbs. In the aves, as we have seen, the type is presented in the natatores, whose name has been adopted as an appropriate term for all the corresponding groups. An enumeration of some other examples of the natatorial type, as the cephalopoda (instanced in the cuttle-fish) in the mollusca; the crustacea (crabs, &c.) in the annulosa; the owls (which often duck for fish) in the raptores; the ichthyosaurus, plesiosaurus, &c., among reptilia, will serve to bring the general character, and its pervasion of the whole animal world, forcibly before the mind of the reader.
The next type is that of meanest and most imperfect organization, the lower termination of all groups, as the typical is the upper. It is called by Mr. Swainson the suctorial, from a very generally prevalent peculiarity, that of drawing sustenance by suction. The acrita, or polypes, among the sub-kingdoms; the intestina, among the annulosa; the tortoises, among the reptilia; the armadillo and scaly ant-eater, pig, mouse, jerboa, and kangaroo, among quadrupeds; the waders and tenuirostres, among birds; the coleoptera, (bug, louse, flea, &c.) among insects; the gastrobranchus, among fishes; are examples which will ill.u.s.trate the special characters of this type. These are smallness, particularly in the head and mouth, feebleness, and want of offensive protection, defect of organs of mastication, considerable powers of swift movement, and (often) a parasitic mode of living; while of negative qualities, there are, besides, indisposition to domestication, and an unsuitableness to serve as human food.
The rasorial type comprehends most of the animals which become domesticated and useful to man, as, first, the fowls which give a name to the type, the ungulata, and more particularly the ruminantia, among quadrupeds, and the dog among the ferae. Gentleness, familiarity with man, and a peculiar approach to human intelligence, are the leading mental characteristics of animals of this type.
Amongst external characters, we generally find power of limbs and feet for locomotion on land, (to which the rasorial type is confined,) abundant tail and ornaments for the head, whether in the form of tufts, crests, horns, or bony excrescences. In the animal kingdom, the mollusca are the rasorial type, which, however, only shews itself there in their soft and sluggish character, and their being very generally edible. In the ptilota, or winged insects, the hymenopterous are the rasorial type, and it is not therefore surprising to find amongst them the ants and bees, "the most social, intelligent, and in the latter case, most useful to man, of all the annulose animals."
As yet the speculations on representation are imperfect, in consequence of the novelty of the doctrine, and the defective state of our knowledge of animated nature. It has, however, been so fully proved in the aves, and traced so clearly in other parts of the animal kingdom, and as a general feature of that part of nature, that hardly a doubt can exist of its being universally applicable. Even in the lowly forms of the acrita, (polypes,) the suctorial type of the animal kingdom, representation has been discerned, and with some remarkable results as to the history of our world. The acrita were the first forms of animal life upon earth, the starting point of that great branch of organization. Now, this sub-kingdom consists, like the rest, of five groups, (cla.s.ses,) and these are respectively representations of the acrita itself, and the other four sub- kingdoms, which had not come into existence when the acrita were formed. The polypi v.a.g.i.n.ati, in the crustaceous covering of the living ma.s.s, and their more or less articulated structure, represent the annulosa. In the radiated forms of the rotifera, and the simple structure of the polypi rudes, we are reminded of the radiata. The mollusca are typified in the soft, mucous, sluggish intestina. And, finally, in the fleshy living ma.s.s which surrounds the bony and hollow axis of the polypi natantes, we have a sketch of the vertebrata. The acrita thus appear as a prophecy of the higher events of animal development. They shew that the n.o.bler orders of being, including man himself, were contemplated from the first, and came into existence by virtue of a law, the operation of which had commenced ages before their forms were realized.
The system of representation is therefore to be regarded as A POWERFUL ADDITIONAL PROOF OF THE HYPOTHESIS OF ORGANIC PROGRESS BY VIRTUE OF LAW. It establishes the unity of animated nature and the definite character of its entire const.i.tution. It enables us to see how, under the flowing robes of nature, where all looks arbitrary and accidental, there is an artificiality of the most rigid kind. The natural, we now perceive, sinks into and merges in a Higher Artificial. To adopt a comparison more apt than dignified, we may be said to be placed here as insects are in a garden of the old style.
Our first una.s.sisted view is limited, and we perceive only the irregularities of the minute surface, and single shrubs which appear arbitrarily scattered. But our view at length extending and becoming more comprehensive, we begin to see parterres balancing each other, trees, statues, and arbours placed symmetrically, and that the whole is an a.s.semblage of parts mutually reflective. It can scarcely be necessary to point to the inference hence arising with regard to the origination of nature in some Power, of which man"s mind is a faint and humble representation. The insects of the garden, supposing them to be invested with reasoning power, and aware how artificial are their own works, might of course very reasonably conclude that, being in its totality an artificial object, the garden was the work of some maker or artificer. And so also must we conclude, when we attain a knowledge of the artificiality which is at the basis of nature, that nature is wholly the production of a Being resembling, but infinitely greater than ourselves.
Organic beings are, then, bound together in development, and in a system of both affinities and a.n.a.logies. Now, it will be asked, does this agree with what we know of the geographical distribution of organic beings, and of the history of organic progress as delineated by geology? Let us first advert to the geographical question.
Plants, as is well known, require various kinds of soil, forms of geographical surface, climate, and other conditions, for their existence. And it is everywhere found that, however isolated a particular spot may be with regard to these conditions,--as a mountain top in a torrid country, the marsh round a salt spring far inland, or an island placed far apart in the ocean,--appropriate plants have there taken up their abode. But the torrid zone divides the two temperate regions from each other by the s.p.a.ce of more than forty-six degrees, and the torrid and temperate zones together form a much broader line of division between the two arctic regions. The Atlantic and Pacific Oceans, and the Persian Gulf, also divide the various portions of continent in the torrid and temperate zones from each other. Australia is also divided by a broad sea from the continent of Asia. Thus there are various portions of the earth separated from each other in such a way as to preclude anything like a general communication of the seeds of their respective plants towards each other. Hence arises an interesting question--Are the plants of the various isolated regions which enjoy a parity of climate and other conditions, identical or the reverse? The answer is--that in such regions the vegetation bears a general resemblance, but the SPECIES are nearly all different, and there is even, in a considerable measure, a diversity of families.
The general facts have been thus stated: in the arctic and antarctic regions, and in those parts of lower lat.i.tudes, which, from their elevation, possess the same cold climate, there is always a similar or a.n.a.logous vegetation, but few species are common to the various situations. In like manner, the intertropical vegetation of Asia, Africa, and America, are specifically different, though generally similar. The southern region of America is equally diverse from that of Africa, a country similar in clime, but separated by a vast extent of ocean. The vegetation of Australia, another region similarly placed in respect of clime, is even more peculiar. These facts are the more remarkable when we discover that, in most instances, the plants of one region have thriven when transplanted to another of parallel clime. This would shew that parity of conditions does not lead to a parity of productions so exact as to include ident.i.ty of species, or even genera. Besides the various isolated regions here enumerated, there are some others indicated by naturalists as exhibiting a vegetation equally peculiar. Some of these are isolated by mountains, or the interposition of sandy wastes. For example, the temperate region of the elder continent is divided about the centre of Asia, and the east of that line is different from the west. So also is the same region divided in North America by the Rocky Mountains. Abyssinia and Nubia const.i.tute another distinct botanical region. De Candolle enumerates in all twenty well-marked portions of the earth"s surface which are peculiar with respect to vegetation; a number which would be greatly increased if remote islands and isolated mountain ranges were to be included.
When we come to the zoology, we find precisely similar results, excepting that man (with, perhaps, some of the less conspicuous forms of being) is universal, and that several tribes, as the bear and dog, appear to have pa.s.sed by the land connexion from the arctic regions of the eastern to those of the western hemisphere. "With these exceptions," says Dr. Prichard, "and without any others, as far as zoological researches have yet gone, it may be a.s.serted that no individual species are common to distant regions. In parallel climates, a.n.a.logous species replace each other; sometimes, but not frequently, the same genus is found in two separate continents; but the species which are natives of one region are not identical with corresponding races indigenous in the opposite hemisphere.
"A similar result arises when we compare the three great intertropical regions, as well as the extreme s.p.a.ces of the three great continents, which advance into the temperate climates of the southern hemisphere.
"Thus, the tribes of simiae, (monkeys,) of the dog and cat kinds, of pachyderms, including elephants, tapirs, rhinoceroses, hogs, of bats, of saurian and ophidian reptiles, as well of birds and other terrene animals, are all different in the three great continents. In the lower departments of the mammiferous family, we find that the bruta, or edendata, (sloths, armadillos, &c.,) of Africa, are differently organized from those of America, and these again from the tribes found in the Malayan archipelago and Terra Australis." {255}
It does not appear that the diversity between the similar regions of Africa, Asia, and America, is occasioned in all instances by any disqualification of these countries to support precisely the same genera or species. The ox, horse, goat, &c., of the elder continent have thriven and extended themselves in the new, and many of the indigenous tribes of America would no doubt flourish in corresponding climates in Europe, Asia, and Africa. It has, however, been remarked by naturalists unacquainted with the Macleay system, that the larger and more powerful animals of their respective orders belong to the elder continent, and that thus the animals of America, unlike the features of inanimate nature, appear to be upon a small scale. The swiftest and most agile animals, and a large proportion of those most useful to man, are also natives of the elder continent. On the other hand, the bulk of the edentata, a group remarkable for defects and meanness of organization, are American. The zoology of America may be said, upon the whole, to recede from that of Asia, "and perhaps in a greater degree," adds Dr. Prichard, "from that of Africa." A much greater recession is, however, observed in both the botany and zoology of Australia.
There "we do not find, in the great ma.s.ses of vegetation, either the majesty of the virgin forests of America, or the variety and elegance of those of Asia, or the delicacy and freshness of the woods of our temperate countries of Europe. The vegetation is generally gloomy and sad; it has the aspect of our evergreens or heaths; the plants are for the most part woody; the leaves of nearly all the plants are linear, lanceolated, small, coriaceous, and spinescent. The gra.s.ses, which elsewhere are generally soft and flexible, partic.i.p.ate in the stiffness of the other vegetables. The greater part of the plants of New Holland belong to new genera; and those included in the genera already known are of new species. The natural families which prevail are those of the heaths, the proteae, compositae, leguminosae, and myrthoideae; the larger trees all belong to the last family." {257}
The prevalent animals of Australia are not less peculiar. It is well known that none above the marsupialia, or pouched animals, are native to it. The most conspicuous are these marsupials, which exist in great varieties here, though unknown in the elder continent, and only found in a few mean forms in America. Next to them are the monotremata, which are entirely peculiar to this portion of the earth. Now these are animals at the bottom of the mammiferous cla.s.s, adjoining to that of birds, of whose character and organization the monotremata largely partake, the ornithorynchus presenting the bill and feet of a duck, producing its young in eggs, and having, like birds, a clavicle between the two shoulders. The birds of Australia vary in structure and plumage, but all have some singularity about them--the swan, for instance, is black. The country abounds in reptiles, and the prevalent fishes are of the early kinds, having a cartilaginous structure.
Altogether, the plants and animals of this minor continent convey the impression of an early system of things, such as might be displayed in other parts of the earth about the time of the oolite. In connexion with this circ.u.mstance, it is a fact of some importance, that the geognostic character of Australia, its vast arid plains, its little diversified surface and consequent paucity of streams, and the very slight development of volcanic rock on its surface, seem to indicate a system of physical conditions, such as we may suppose to have existed elsewhere in the oolitic era: perhaps we see the chalk formation preparing there in the vast coral beds frontiering the coast. Australia thus appears as a portion of the earth which has, from some unknown causes, been belated in its physical and organic development. And certainly the greater part of its surface is not fitted to be an advantageous place of residence for beings above the marsupialia, and judging from a.n.a.logy, it may yet be subjected to a series of changes in the highest degree inconvenient to any human beings who may have settled upon it.
The general conclusions regarding the geography of organic nature, may be thus stated. (1.) There are numerous distinct foci of organic production throughout the earth. (2.) These have everywhere advanced in accordance with the local conditions of climate &c., as far as at least the cla.s.s and order are concerned, a diversity taking place in the lower gradations. No physical or geographical reason appearing for this diversity, we are led to infer that, (3,) it is the result of minute and inappreciable causes giving the law of organic development a particular direction in the lower subdivisions of the two kingdoms. (4.) Development has not gone on to equal results in the various continents, being most advanced in the eastern continent, next in the western, and least in Australia, this inequality being perhaps the result of the comparative antiquity of the various regions, geologically and geographically.
It must at the same time be admitted that the line of organic development has nowhere required for its advance the whole of the families comprehended in the two kingdoms, seeing that some of these are confined to one continent, and some to another, without a conceivable possibility of one having been connected with the other in the way of ancestry. The two great families of quadrumana, cebidae and simiadae, are a noted instance, the one being exclusively American, while the other belongs entirely to the old world. There are many other cases in which the full circular group can only be completed by taking subdivisions from various continents. This would seem to imply that, while the entire system is so remarkable for its unity, it has nevertheless been produced in lines geographically detached, these lines perhaps consisting of particular typical groups placed in an independent succession, or of two or more of these groups. And for this idea there is, even in the present imperfect state of our knowledge of animated nature, some countenance in ascertained facts, the birds of Australia, for example, being chiefly of the suctorial type, while it may be presumed that the observation as to the predominance of the useful animals in the Old World, is not much different from saying that the rasorial type is there peculiarly abundant. It does not appear that the idea of independent lines, consisting of particular types, or sets of types, is necessarily inconsistent with the general hypothesis, as nothing yet ascertained of the Macleay system forbids their having an independent set of affinities. On this subject, however, there is as yet much obscurity, and it must be left to future inquirers to clear it up.
We must now call to mind that the geographical distribution of plants and animals was very different in the geological ages from what it is now. Down to a time not long antecedent to man, the same vegetation overspread every clime, and a similar uniformity marked the zoology.
This is conceived by M. Brogniart, with great plausibility, to have been the result of a uniformity of climate, produced by the as yet unexhausted effect of the internal heat of the earth upon its surface; whereas climate has since depended chiefly on external sources of heat, as modified by the various meteorological influences. However the early uniform climate was produced, certain it is that, from about the close of the geological epoch, plants and animals have been dispersed over the globe with a regard to their particular characters, and specimens of both are found so isolated in particular situations, as utterly to exclude the idea that they came thither from any common centre. It may be asked,--Considering that, in the geological epoch, species are not limited to particular regions, and that since the close of that epoch, they are very peculiarly limited, are we to presume the present organisms of the world to have been created ab initio after that time? To this it may be answered,--Not necessarily, as it so happens that animals begin to be much varied, or to appear in a considerable variety of species, towards the close of the geological history. It may have been that the mult.i.tudes of locally peculiar species only came into being after the uniform climate had pa.s.sed away. It may have only been when a varied climate arose, that the originally few species branched off into the present extensive variety.
A question of a very interesting kind will now probably arise in the reader"s mind--WHAT PLACE OR STATUS IS a.s.sIGNED TO MAN IN THE NEW NATURAL SYSTEM. Before going into this inquiry, it is necessary to advert to several particulars of the natural system not yet noticed.
It is necessary, in particular, to ascertain the grades which exist in the cla.s.sification of animals. In the line of the aves, Mr.
Swainson finds these to be nine, the species pica, for example, being thus indicated:-
Kingdom Animalia.
Sub-kingdom Vertebrata.
Cla.s.s Aves.
Order Incessores.
Tribe Conirostres.
Family Corvidae.
Sub-family Corvinae.
Genus Corvus.
Sub-genus, or species Pica.
This brings us down to species, the subdivision where intermarriage or breeding is usually considered as natural to animals, and where a resemblance of offspring to parents is generally persevered in. The dog, for instance, is a species, because all dogs can breed together, and the progeny partakes of the appearances of the parents. The human race is held as a species, primarily for the same reasons.
Species, however, is liable to another subdivision, which naturalists call variety; and variety appears to be subject to exactly the same system of REPRESENTATION which have been traced in species and higher denominations. In canis, for instance, the bull-dog and mastiff represent the ferocious sub-typical group; the waterdog is natatorial; we see the speed and length of muzzle of the suctorial group in the greyhound; and the bushy tail and gentle and serviceable character of the rasorial in the shepherd"s dog and spaniel. Even the striped and spotted skin of the tiger and panther is reproduced in the more ferocious kind of dogs--an indication of a fundamental connexion between physical and mental qualities which we have also seen in the zebra, and which is likewise displayed in the predominance of a yellow colour in the vultures and owls in common with the lion and his congeners.
It is by no means clearly made out that this system of nine gradations over and above that of variety applies in all departments of nature. On the contrary, even Mr. Swainson gives series in which several of them are omitted. It may be that, in some departments of nature, variation from the cla.s.s or order has gone down into fewer shades than in others; or it may be, that many of the variations have not survived till our era, or have not been as yet detected by naturalists; in either of which cases there may be a necessity for shortening the series by the omission of one or two grades, as for instance TRIBE or SUB-FAMILY. This, however, is much to be regretted, as it introduces an irregularity into the natural system, and consequently throws a difficulty and doubt in the way of our investigating it. With these preliminary remarks, I shall proceed to inquire what is the natural status of man.
That man"s place is to be looked for in the cla.s.s mammalia and sub- kingdom vertebrata admits of no doubt, from his possessing both the characters on which these divisions are founded. When we descend, however, below the CLa.s.s, we find no settled views on the subject amongst naturalists. Mr. Swainson, who alone has given a review of the animal kingdom on the Macleay system, unfortunately writes on this subject in a manner which excites a suspicion as to his judgment. His arrangement of the first or typical order of the mammalia is therefore to be received with great hesitation. It is as follows:-
Typical Quadrumana Pre-eminently organized for grasping.
Sub-typical Ferae . . . Claws retractile; carnivorous.
Natatorial Cetacea. . Pre-eminently aquatic; feet very short.