52 



THE GENESIS OF SPECIES. 



[ClIAP. 



liave taken place in tlie coinpanitively short time occupied 

 by the evolution of tiiese special lish forms, we might cer- 

 tainly expect other and far more bizarre structures would 

 (did not some law forbid) have been develo[)ed fnjm other 

 rujrosities. in the manifold exiofencies of the multitudinous 

 organisms which must (on the Darwinian hypothesis) have 

 been gradually evolved during the enormous period inter- 

 vening between the first appearance of vertebrate life and 

 the present day. Yet with these exceptions, the position 

 of the limbs is constant from the lower iishes up to man, 

 there being always an anterior pectoral pair placed in front 

 of a posterior or pelvic pair when both are present, and in 

 no single instance are there more than these two pairs, 



••c^ 



UOUTU OF A WUALE. 



The development of whalebone (baleen) in th& mouth 

 of the whale is another dilTiculty. A whale's mouth is fur- 



