166 R. S. Lull — The Evolution of the Horse Family. 



the same. Still, it is curious to note that, among living horses, 

 in instances of reversion to ancestral conditions the fore foot Lb 

 more apt to exhibit well-developed atavistic toes, showing that 

 in it the reminiscent tendencies are stronger. 



The Yale collection contains specimens representing three 

 examples of the occurrence of extra toes in the modern horse. 

 They may be monstrosities of the same nature as the occasional 

 sixth finger in man and the multiple digits frequently occur- 

 ring in the domestic cat. They seem, however, to have a 

 deeper significance and to be true cases of atavism, or reversal 

 to an ancestral condition, although they are abnormal in the 



Fig. 5. a, Fore foot and b, hind foot of Clique, "a multitoed modern 

 horse. One-eighth natural size. (After Marsh.) 



development of one lateral digit only, as we know of no two- 

 toed fossil horses. Not only has the toe itself reappeared, but 

 in the wrist and ankle are bones with all their old forms and 

 associations, which have not been normally present since Oli- 

 gocene times. Pliny, the elder, who lost his life in the 

 destruction of Pompeii, A. D. 79, tells us in his Natural His- 

 tory : " It is said, also, that Csesar the dictator had a horse 

 which would allow no one to mount him but himself, and that 

 its fore-feet were like those of a man." Unquestionably this 



