242 PRINCIPLES OF STOCK-BREEDING. 



of wilf and the posterior masses of the brain the 

 seats of desire or aversion by which will is excited 

 ought to accompany the locomotive system, not mere- 

 ly in the greater masses of the figure, but even in the 

 muscles of the face." l 



It may be that this ought to be the case, but Na- 

 ture has, unfortunately for herself or the theory, de- 

 veloped the structures so closely associated from quite 

 different portions of the blastodermic membrane of 

 the embryo. 



As the peculiarities of hybrids are relied upon as 

 furnishing the most conclusive evidence of the truth 

 of this theory, an examination of this part of the argu- 

 ment will be of particular interest. 



" The mule," says Mr. Orton, " the produce of the 

 male ass and the mare, is essentially a modified ass / 

 the ears are those of an ass somewhat shortened ; the 

 mane is that of the ass, erect ; the tail is that of an 

 ass ; the skin and color are those of an ass somewhat 

 modified ; the legs are slender, and the hoofs high, 

 narrow, and contracted, like those of an ass ; in fact, 

 in all these respects it is an ass somewhat modified. 

 The body and barrel of the mule are round and full, 

 in which it differs from the ass and resembles the 

 mare. The hinny a (or muto), on the other hand, the 

 produce of the stallion and she-ass, is essentially a 

 modified horse ; the ears are those of a horse some- 

 what lengthened ; the mane flowing ; the tail is bushy, 

 like that of a horse ; the skin is finer, like that of a 

 horse; and the color varies also like the horse; the 



1 Walker on " Intermarriage," pp. 143, 144. 



2 Bardeau of the French. 



