THE CONVERGENCE OF THE EVIDENCES. 555 



there could be no rational hesitation which of the two views 

 should be entertained. 



§ 172. Further means of judging, however, we found to 

 be afforded by bringing the two hypotheses face to face with 

 the general truths established by naturalists. These induc- 

 tive evidences were dealt with in four chapters. 



'"'The Arguments from Classification" were these. Organ- 

 isms fall into groups within groups ; and this is the arrange- 

 ment 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-groups 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 those here supposed to have been evolved. And 

 then there is the further significant fact, that divergent 

 groups are allied through their lowest rather than their high- 

 est members. 



Of "the Arguments from Embryology," the first is that 

 when developing embryos are traced from their common 

 starting point, and their divergences and re-divergences 

 symbolized by a genealogical tree, there is manifest a general 

 parallelism between the arrangement of its primary, second- 

 ary, and tertiary branches, and the arrangement of the di- 

 visions and sub-divisions of our classifications. Nor do the 

 minor deviations from this general parallelism, which look 

 like difficulties, fail, on closer observation, to furnish addi- 

 tional 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. 



We next considered "the Arguments from Morphology." 

 Apart from those kinships among organisms disclosed by 

 their developmental changes, the kinships which their adult 



