Part 7 (1/2)
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.