Page:Popular Science Monthly Volume 5.djvu/597

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THE CHAIN OF SPECIES.
579

growth; and we see long lateral branches, likewise, similarly tipped with leaf, bud, and bloom; and we do not doubt their common origin, because there stands the common connecting trunk. Yet neither of these had any part in the production of the others; nor remains there a single one of the individual buds and tender leaves which, in the years gone by, really did take part in the development, the consummation whereof we now behold.

Nor, in regarding man, whom we fondly believe the crowning glory of creation, should we expect to see the precise yearly growths which have finally lifted him to this elevation. The steps of the evolution may still be traced, but not a single individual of the lineal ancestry remains. When, therefore, we speak of the chain of species—of the line of man's descent—upon a priori grounds, we do not expect to find, extant in life, the very links of the chain. The loss of them is another proof of evolution. It is thus, according to the plan proposed, we would expect to find it exemplified. It is a rational conception of creation we are attempting to reach, and no other rational hypothesis has ever been proposed.

We do not find, then, the very species through which the ascent to man has been accomplished, and do not seek to find them; but, if this plan of derivation is well founded, as it is clearly rational, we must conclude that the various races of man, now upon the earth, sprang from some common stock, of the order of primates; which, in turn, must have been derived from a lower simian form; and this, again, must have come of a trunk leading back to aplacental mammals; and these lead on to amphibious reptiles; these to fishes; these to cephalopod mollusks; these to bivalve mollusks; these to cirrhiped crustaceæ; which last, in fœtal life, possess all the characteristics of the general articulate or annulose type; annulosa being derived directly from primordial cœlenterata, whence probably issued, also, annuloids and molluscoids. If molluscoidea be the offspring of cœlenterata, then the part played in evolution by the molluscoid type was not to furnish a stage of transition, but to illustrate the power of a segment. In any case, we end with the cœlenterate type, whether fixed, as in actinia, or occasional only, as in rhizopods. This last, being the first animal form, causes us to remember that here branches off another great kingdom, of which, the life is always exothentic; and which, therefore, has no direct part in this chain, except that its first forms furnish the common stock whence has arisen all organic life.

This wonderfully intimate relationship of the innumerable forms of living creatures, properly considered, is calculated to elevate our conception of the creation, and of man himself; while, to the glory of the Creator, it is held out to us as another "bow of promise"—another assurance of the certainty of the universal reign of law. Nor must it be forgotten that it does not exclude, but, contrariwise, encourages, moral reflections. While it tells man of his dignity, it tells him