The inductive evidences for the evolutionary hypothesis, as contra-distinguished from the special-creation hypothesis, are dealt with in four chapters. The "Arguments from Classification" are these: Organisms fall into groups within groups; and this is the arrangement which we see results from evolution where it is known to take place. Of these groups within groups, the great or primary ones are the most unlike, the sub-groups are less unlike, the sub-sub-group still less unlike, and so on; and this, too, is a characteristic of groups demonstrably produced by evolution. Moreover, indefiniteness of equivalence among the groups is common to those which we know have been evolved, and to those supposed in the volume before us to have been evolved. There is the further significant fact that divergent groups are allied through their lowest rather than their highest members. Of the "Arguments from Embryology," the first is that, when developing embryos are traced from their common starting-point, and their divergencies and re-divergencies are symbolized by a genealogical tree, there is manifest a general parallelism between the arrangement of its primary, secondary, and tertiary branches, and the arrangement of the divisions and subdivisions of Mr. Spencer's classifications. Nor do the minor deviations from this general parallelism, which look like difficulties, fail on closer observation to furnish additional evidence; since those traits of a common ancestry which embryology reveals are, if modifications have resulted from changed conditions, liable to be disguised in different ways and degrees, in different lines of descendants. Mr. Spencer next considers the "Arguments from Morphology." Apart from those kinships among organisms disclosed by their developmental changes, the kinships which their adult forms show are profoundly significant. The unities of type found under such different externals are inexplicable, except as results of community of descent, with non-community of modification. Again, each organism analyzed apart shows, in the likenesses obscured by unlikenesses of its component parts, a peculiarity which can be ascribed only to the formation of a more heterogeneous organism out of a more homogeneous one. And, once more, the existence of rudimentary organs, homologous with organs that are developed in allied animals or plants, while it admits of no other rational interpretation, is satisfactorily interpreted by the hypothesis of evolution. Last of the inductive evidences are the "Arguments from Distribution." While the facts of distribution in space are unaccountable as results of designed adaptation of organisms to their habitats, they are accountable as results of the competition of species, and the spread of the more fit into the habitats of the less fit, followed by the changes which new conditions induce. Though the facts of distribution in time are so fragmentary that no positive conclusion can