2?6 THE EVOLUTION OF MAN. 



summed up the general result of his investigations in Mor- 

 phology is especially appropriate : 



" All forms have a resemblance ; none is the same as another, 

 And their chorus complete points to a mystical law." * 



Now that, by the Theory of Descent, we have discovered 

 this " mystical law," have solved this " sacred enigma," now 

 that we can explain the similarity of forms by Heredity, 

 and their dissimilarity by Adaptation, we can find no 

 weapon in the whole rich arsenal of Comparative Anatomy 

 which defends the truth of the Theory of Descent more 

 powerfully than the comparison of the internal skeletons 

 of the various Vertebrates. We may, therefore, expect 

 A priori that such comparison is of special importance in 

 our History of the Evolution of Man. The inner vertebrate 

 skeleton is one of those organs as to the Phylogeny of 

 which Comparative Anatomy affords us conclusions far 

 more important and deeper than those to be gained from 

 its Ontogeny. 176 



More than any other system of organs, the internal 

 skeleton of Vertebrates, when studied comparatively, clearly 

 and immediately impresses the observer with the necessity 

 of the phylogenetic connection between these allied and yet 

 very varied forms. A thoughtful comparison of the bony 

 frame of Man with that of other Mammals, and of these 

 again with that of lower Vertebrates, is alone sufficient to 

 afford conviction of the true tribal relationship of all 

 Vertebrates. All the separate parts of which this bony 

 frame is composed appear in other Mammals, in a great 



* ' Alle Gestalten Bind ahnlich, doch keine gleichet der andernj 

 Und so deutet dor Chor auf ein gehehnes Gesetz." 



