no idea even of opening the question as to what work the Darwinian theory has incited, and in what way the work done has reacted upon the theory; and least of all do we like to meddle with the polemical literature of the subject, already so voluminous that the German bibliographers and booksellers make a separate class of it.  But two or three treatises before us, of a minor or incidental sort, suggest a remark or two upon the attitude of mind toward evolutionary theories taken by some of the working naturalists.

Mr. Darwin’s own expectation, that his new presentation of the subject would have little or no effect upon those who had already reached middle-age, has—­out of Paris—­not been fulfilled.  There are, indeed, one or two who have thought it their duty to denounce the theory as morally dangerous, as well as scientifically baseless; a recent instance of the sort we may have to consider further on.  Others, like the youth at the river’s bank, have been waiting in confident expectation of seeing the current run itself dry.  On the other hand, a notable proportion of the more active-minded naturalists had already come to doubt the received doctrine of the entire fixity of species, and still more that of their independent and supernatural origination.  While their systematic work all proceeded implicitly upon the hypothesis of the independence and entire permanence of species, they were perceiving more or less clearly that the whole question was inevitably to be mooted again, and so were prepared to give the alternative hypothesis a dispassionate consideration.  The veteran Lyell set an early example, and, on a reconsideration of the whole question, wrote anew his famous chapter and reversed his former and weighty opinion.  Owen, still earlier, signified his adhesion to the doctrine of derivation in some form, but apparently upon general, speculative grounds; for he repudiated natural selection, and offered no other natural solution of the mystery of the orderly incoming of cognate forms.  As examples of the effect of Darwin’s “Origin of Species” upon the minds of naturalists who are no longer young, and whose prepossessions, even more than Lyell’s, were likely to bias them against the new doctrine, two from the botanical side are brought to our notice through recent miscellaneous writings which are now before us.[VI-2]

Before the publication of Darwin’s first volume, M. Alphonse de Candolle had summed up the result of his studies in this regard, in the final chapter of his classical “Geographie Botanique Raisonnee,” in the conclusion, that existing vegetation must be regarded as the continuation, through many geological and geographical changes, of the anterior vegetations of the world; and that, consequently, the present distribution of species is explicable only in the light of their geological history.  He surmised that, notwithstanding the general stability of forms, certain species or quasi-species might have originated through diversification