72 Darivin, and after Darzuin. 



full agreement with the theory of evolution, while 

 they offer serious difficulties to the theory of special 

 creation. As Darwin remarks, it is hard to imagine 

 conditions of life more similar than those furnished by 

 deep 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 useless foot-stalks for the imaginary sup- 

 port 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 Prof. 

 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 designated— in accordance with 

 the theory of descent — obsolescent or vestigial struc- 

 tures. It is, however, of great importance to add that 

 these structures are of such general occurrence through- 

 out 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 impos- 

 sible to find a single species which does not in this 



