DIFFERENT SYSTEMS. 107 



preflion of the male feed remained in the eggs, 

 and that it was only by contagion that they 

 were impregnated, &c. 



It is likewife proper to remark, that what Har- 

 vey has fiiid concerning the parts of generation 

 of the cock is by no means exad:. He affirms, 

 that the cock lias no penis capable of entering 

 the vagina of the hen. It is certain, however, 

 that this animal, in place of one penis, has a 

 couple, which both adt at the fame time ; and 

 this action is a vigorous compredion, if not an 

 adual copulation *. It is by this double organ 

 that the cock throws his feminal liquor into the 

 uterus of the hen. 



Let us now compare Flarvey's experiments 

 upon female deer with thofe of De Graafl' upon 

 female rabbits ; and, though De Graaff believed, 

 as Harvey did, that all animals proceed from 

 eggs, we fhall find a great difference in the 

 manner in which thefe two anatomifts have per- 

 ceived the firft formation, or rather the expan- 

 fion, of the foetufes of viviparous animals. 



After exerting every effort to prove, by ar- 

 guments drawn from comparative anatomy, that 

 the tellicles of viviparous females are true ova- 

 ria, Graaff explains the manner in which the 

 eggs are detached from tire ovaria, and fall into 

 the honis of the uterus. He then relates the 

 remarks he made upon a rabbit which he dif- 

 fciftcd half an hour after copulation. The horns 



of 



* See Regn. Graaf, p. 242. 



