74 EVOLUTION GENETICS, AND EUGENICS 



limestone caverns under nearly the same climate in the two continents 

 of America and Europe; so that, in accordance with the theory of 

 special creation, very close similarity in the organizations of the two 

 sets of faunas might have been expected. But, instead of this, the 

 affinities of these two sets of faunas are with those of their respective 

 continents — as of course they ought to be on the theory of evolution. 

 Again, what would have been the sense of creating the useless foot- 

 stalks for the imaginary support of absent eyes, not to mention all the 

 other various grades of degeneration in other cases ? So that, upon 

 the whole, if we agree with the late Professor Agassiz in regarding 

 these cave animals as furnishing a crucial test between the rival 

 theories of creation and evolution, we must further conclude that the 

 whole body of evidence which they now furnish is weighing on the 

 side of evolution. 



So much, then, for a few special instances of what Darwin called 

 rudimentary structures, but what may be more descriptively desig- 

 nated — in accordance with the theory of descent — obsolescent or 

 vestigial structures. It is, however, of great importance to add that 

 these structures are of such general occurrence throughout both the 

 vegetable and animal kingdoms that, as Darwin has observed, it is 

 almost impossible to point to a single species which does not present 

 one or more of them. In other words, it is almost impossible to find 

 a single species which does not in this way bear some record of its own 

 descent from other species; and the more closely the structure of any 

 species is examined anatomically, the more numerous are such records 

 found to be. Thus, for example, of all organisms that of man has 

 been most minutely investigated by anatomists; and therefore I think 

 it will be instructive to conclude this chapter by giving a list of the 

 more noteworthy vestigial structures which are known to occur in the 

 human body. I will take only those which are found in adult man, 

 reserving for the next chapter those which occur in a transitory manner 

 during earlier periods of his life. But, even as thus restricted, the 

 number of obsolescent structures which we all present in our own 

 person is so remarkable, that their combined testimony to our descent 

 from a quadrumanous ancestry appears to me in itself conclusive. 

 I mean, that even if these structures stood alone, or apart from any 

 more general evidences of our family relationships, they would be 

 sufficient to prove our parentage. Nevertheless, it is desirable to 

 remark that of course these special evidences which I am about to 

 detail do not stand alone. Not only is there the general analogy 



