It is but a very imperfect sketch which we have thins been able to give of Darwin's theory, and of the arguments by which it, is supported Whatever may be thought of the troth of the theory, it must be ndmitted to be admirably framed and guarded, end to be maintained not only with great ingenuity of argument, but by the aid of a vast store of scientific information, most skillfully used. Its opponents condemn it as resting on 'unwarrantable assumptions, and demand some proof, for example, of the transition of organs from a simple or rudimentary to a complex and more perfect state. They also refuse to acknowledge such imperfection of the geological record as Darwin's argument demands, and they insist much on the completeness of the changes which that record discloses, and the absence of transitional forms both among fossils and existing species. Much of what Darwin and other advocates of the same general views contend for. they admit; a cm lain power of development in organic nature, a "struggle for life," and " eatural selection ;" but they regard the limits of development and variation ae com paratively narrow. Nor would the state of the question, as they believe, be materially affected, if many of what have hitherto generally been regarded as species, should be proved lo be mere varieties. Any number of such errors of naturalists might be exposed and corrected, without modification of our views of the laws of nature; and errors of this kind are precisely such as might be expected, when the forms of organic life began to be discovered and described, and ere yet there was time for their mature study in all parts cf the world, and under all various circumstances.
The doctrine of Darwin, or the Ero/mtion. Theory as it is usually named, continues to be it fruitful source of controversy. It has found many adhen.nts in all countries, and its leading principle—" the survival of the fittest"—bas been applied in other fields of inquiry besides natural history. I: ought to lie mentioned that the eminent naturalist, A. It. Wallace, unaware of the speculations Mr. Darwin was engaged it, had elaborated independently a very similar scheme: tlw prior publication labors was chiefly accideetal. The opponents of Darwinism arc perhaps more numerous than its adherents. The majority greniad their arguments on the dangers they apprehend from it ; they believe that its reception would can the foundations of religion and social order. But men of science bring against it a formidable array of more legitimate arguments. many of which it is found difficult to answer satisfactorily. Nevertheless the doctrine seems to be working its way into general acceptance.
•