1902.] 



HAIR-SLOPE IN MAMMALS. 



157 



These degrees of development in three familiar animals are 

 suggestive as to the well-known differences in their locomotive 

 activity. 



Text-fig. 31. 



Domestic Horse, showing the hair-streams, feathering, and whorls. 



It may be remarked that the Prejevalsky's Horses in the Society's 

 Gardens exhibit small whorls, featherings, and crests, more 

 like those occasionally found in the Ass than those of a Mule or 

 Horse, and that no Zebras of the various species examined show 

 any- traces of this arrangement of hair ; also that Eqtms onager, in 

 the Society's Gardens, alone shows a large whorl, feathering, and 

 ci-est, like those of a Mule, but wider and better developed. 



One may now ask, after the review of these evidences as to the 

 connection of the habits of animals with arrangements of hair, 

 whether it is not shown that they cany about them clear traces 

 of their habits, passive and active, which are peculiar to them and 

 to a long line of ancestors. 



In this view, whorls, featherings, and crests may be looked upon 

 as by-products of muscular activity. If this be allowed, it is 

 highly instructive to note what muscular activity is capable of 

 doing, as to modifying the direction of hair, a structure itself not 

 concerned in muscular action ; and it is not less important from 

 the point of view of inheritance to note that very long- continued 



