obligation to abstain from wantonly injuring them, and as far as possible, to cherish and protect them. Good men feel this duty, as if it were a command from a source above themselves. It seems to them, that if the helplessness of childhood calls for kind and gentle treatment, much more does the essentially weaker character of the dumb creature. And if the innocence of infancy is touching, still more so is the even more harmless character, which (overlooking carnivorous instincts implanted in certain families for a wise purpose) attaches to the lower animals. It is common, under the influence of prejudice, to do gross injustice to the characters of these denizens of nature's common. We do not sufficiently reflect on their respectable qualities. Yet we must go to the dog for a type of the virtue of fidelity, and to the bee for that of industry. The parental affection of many animals is not below, if it is not considerably above, that of human mothers. Man nowhere exemplifies the virtue of patience, in the practical perfection in which we see it in the horse and many other creatures which become the slaves of his convenience. Nowhere does he display that perfect moderation in wants. Alas for man's boasted superiority-in how many respects does it fail beside the unassuming merits of the mere commonality of nature!

185

AFFINITIES AND GEOGRAPHICAL

DISTRIBUTION OF ORGANISMS.

ALL truth being self-consistent, we might expect that this view of the history of organic nature, if sound, would accord with a just classification of Plants and Animals, supposing such to exist. It is certainly very desirable that our hypothesis could have been subjected to this test; but it cannot be, for naturalists are as yet only struggling towards true classifications in both kingdoms. We may, nevertheless, make some inquiry into at least the general lineaments of that order which has long been alleged to exist in animated nature, with a view to ascertaining how far any such order agrees with a genealogical system.

The result of any investigations which I have been able to make, is, that there is an order in animated nature, but that it has hitherto been much misunderstood. We see some pointing to that "chain of being," or series of ascending forms, which has long been supposed to extend between the animalcule and the human being. It has been on the other hand successfully shown that beings do not form "a single and continuous series;" that it is "impossible to place all living animals in such an order that we may always pass from one species to another by following a decrease in perfection." "On the one hand, there are classes of animals so insulated, that nothing connects them with others." "On the other, there are types of organization which are abso

lutely indivisible, and of which the most perfect beings are superior to the mean of another type, while the most imperfect are inferior to it." A solution for the difficulty may be found, if we contemplate the animal kingdom (and, by consideration of parity, we may presume the vegetable also) as consisting of a plurality of series going on side by side with each other, but not all to the same point in the scale. Nor is this merely a hypothetical view of the animal kingdom. It is strongly pointed to by some of the most interesting discoveries in embryology. It is supported by several important considerations regarding the general characters of particular series. It likewise harmonizes with that order of fossils, which may be said to form a sort of rude outline of the history of organization upon earth. Finally, such reformation as this new view calls for in classifications, is accordant in its general demands with all those recently effected by the greatest naturalists, by which external and comparatively accidental characters are overlooked, and only the more essential affinities regarded. If it goes beyond the march of living naturalists, it goes in the direction in which they are going, and over ground to which I believe they must quickly come, whether they adopt a genealogical view of the organic world or not.

The divisions of the animal kingdom, as we find them in Cuvier, are partly into grades, with a regard to dignity of organizationfirst into Vertebrata (having an internal skeleton) and Invertebrata, and afterwards into such divisions as these of the vertebrata —namely, Mammalia, Birds, Reptiles, Fishes. In these grades are comprehended animals of very various character,—animals which only agree in this particular of a community of grade or rank. But other divisions in the common classifications are into groups or series of animals closely allied to each other in form, and of one general character,—as, for example, the cephalopoda, the echinodermata, the crustacea. The one kind of division may be said to be transverse, the other longitudinal. Such a diversity gives rise to a suspicion that there is something wrong, something out of accordance with nature. And so it is. The true funda

mental divisions are entirely of the latter kind-longitudinal; there only do we find persistence of characters; the other socalled divisions are only the marks of stages which the true divisions, the Stirpes of being, have reached in their respective courses. It is nevertheless necessary, in the meantime, to keep the existing classification in view, and to use its language, in order that my own views may be intelligible.

Cuvier divided the Invertebrata into three great masses, the Radiata, the Articulata, and Mollusca. Of these, the two last appear as co-ordinate, though distinct from each other; while the Radiata, again, may be considered as forming a kind of basis for the whole kingdom.

The RADIATA are all of them animals of exceedingly simple structure, mostly inhabitants of the waters, many of them propagating not by ova, but by division of their bodies, or by the throwing out of little bud-like excrescences. In this lower region are comprehended the Infusory animalcules, Internal Parasites (Entozoa), Sponges, Polyps, Sea-nettles (Acalepha), and some other obscure classes. Some of these appear to be distinct and independent series, which advance no further; such, in particular, are the internal parasites, which necessarily do not pass to any higher grade, because they have no sphere for further development. Others form the roots, as it were, of higher families.

There are two admitted methods of investigating the affinities of beings. One is to observe the connexion between the forms of the mature organisms; another is to examine the embryotic progress, and watch the succession of forms there presented. It is ascertained that no animal, in the course of its development, passes through the forms of all the animals meaner than itself. For example, the sea-nettle is at one time like the monad, an infusory animalcule, and then like the polyp; the mollusk is successively like the monad and polyp, but never like the seanettle. The articulate animal, again, is never like the polyp or sea-nettle, but proceeds at once from the monad form to that of the worm. This Professor Owen calls being "obedient to the law

of unity of organization only in its monad stage." The fact has been held as a difficulty in the way of the doctrine of unity; but perhaps it is only one of the same nature with that intimated regarding the assumed scale of being. I see animals classed by their affinities in distinct lines, or series, which I regard as stirpes or races. I would therefore expect the unity of organization to be liable to some such limitation as Mr. Owen points out. Is it not, in reality, that each stirps has a unity of organization for itself, or, in other words, that there is such a unity only as far as each particular series of animals is concerned? These breaks in unity, and the breaks in the chain of being, are but one thing: they are only disturbances to our preconceived ideas, not to a true view of nature drawn from its realities.

FIG. 80.

I shall not attempt to place all these obscure animals in genealogical series. The state of zoological science demands that such an effort should be postponed. Let us limit our attention to one class, the Echinodermata, or star-fishes, which are perhaps improperly ranked with other Radiata, seeing that their character is so much superior. In general highly organized, and enjoying free movement at the bottom of the sea, these animals are signally destructive. Admitted to be in their lower forms intimately allied to the Polyps, they probably start in some portion of that extensive order. One of their earliest forms is the Encrinus or stone-lily, a group of animals of which we have seen many varieties flourishing in the early seas, but which are now nearly extinct. The creature consisted of a stomach and mouth, surrounded by long tentacles or arms, placed upon the top of a stalk fixed to the sea-bottom, the whole being composed of numberless minute calcareous moniliformis. plates, connected by gelatinous substance. In more

དའ། འགར། (0EED

Encrinites

'Lectures on the Invertebrate Animals, p. 369.