in ANCESTORS OF WHALES 177 



exclusively for oceanic life, it yet pos- 

 sesses in a rudimentary form some of the 

 most characteristic bones of the terrestrial 

 Mammalia. Upon the assumption that 

 no organic structure can possibly have 

 any other origin than ordinary generation, 

 and that they can never have been origin- 

 ated except by actual use, nor be found 

 incomplete except as the consequences 

 of disuse, then of course the conclusion 

 seems unavoidable that the Whale is the 

 lineal descendant, by ordinary generation, 

 of some animal that once walked upon 

 the land. Accordingly, I have heard a 

 very high authority on Biological science 

 declare that not only did he accept this 

 conclusion, but that he could conceive 

 no other solution of the problem pre- 

 sented by the facts. 



Yet it is evident that it rests entirely 

 on the two preliminary assumptions above 

 specified. Of the first of these two as- 



N 



