RELATIVE INFLUENCE OF PARENTS. 247 



was colored more like the jennet than most mules, 

 but I have seen many with similar markings, and 

 many more like the horse in style and finish than it 

 was." l 



The difference in the voice of the mule and the 

 hinny, that Mr. Orton urges as an important part of 

 his argument, requires a passing notice. The larynx 

 is the organ of voice in mammals, and modifications 

 of its form give rise to the various sounds emitted by 

 different species of animals. In the ass the vocal liga- 

 ments are inserted in an arched cavity. " On each 

 side of this cavity are two circular apertures, which 

 lead to two large sacs situated behind the mucous 

 membrane, between the vocal ligaments and internal 

 surface of the thyroid." a 



The characteristic bray of the ass is produced by 

 this peculiar conformation of the larynx; and the 

 mule, inheriting the same structure, is endowed with 

 a similar voice. As the larynx is not developed from 

 the layer of the blastodermic membrane that gives 

 rise to the locomotive organs, the argument of Mr. 

 Orton, in regard to the peculiarities of the voice of 

 the mule and the hinny, is without foundation. 



" A cross between a male wolf and a bitch," says 

 Mr. Orton, "illustrates the same law, the offspring 

 having a markedly wolfish aspect, skin, color, ears, 

 and tail. On the other hand, a cross between the dog 

 and female wolf afforded animals much more dog-like 

 in aspect, slouched ears, and even pied in color. 



1 Loc. dt., p. 170. 



2 " Cyclopaedia of Anatomy and Physiology," vol. iv., p. 1492 ; 

 Journal of the Highland Agricultural Society, 1857-'59, p. 22. 



