4 



THE HORSE 



The anatomy and history of the horse are, more- 

 over, often taken as affording a test case of the value 

 of the theory of evolution, or, at all events, of the 

 doctrine that animal forms have been transmuted or 

 modified one from another with the advance of time, 

 whether, as extreme evolutionists hold, by a spontaneous 

 or inherent evolving or unrolling process, or, as many 

 others are disposed to think, by some mysterious and 

 supernatural guidance along certain definite lines of 

 change. It will be observed that both these views 

 are opposed to the doctrine, formerly held universally 

 by naturalists and theologians alike, that each modifica- 

 tion of animal or plant form sufficiently distinct to be 

 called a species had a separate origin — a doctrine for 

 which, it may be remarked by the way, no proof of any 

 kind has ever been offered. 



The evidence in favour of the theory of transmuta- 

 tion afforded by the case of the horse is derived from 

 two distinct sources — (1) The structure of existing 

 horses ; (2) the past history of the race as revealed by 

 fossil remains. 



(1) By far the most interesting portions of the 

 organisation of existing horses from this point of view 

 are the various rudimentary and apparently useless 

 structures which occur in several parts of its body, 

 structures which correspond to some which are fully 

 developed and functional in other animals, but which, 



