OP THE GENITAL FUNCTION IN MAN. 333 



considerable length of time. The same was discovered in two 

 cases, where, by mal-formation, one testicle had no commu- 

 nication with the corresponding vesicle. In the gelding and the 

 stallion their contents are similar and nearly equal in quantity. 

 The vas deferens has no communication in some animals with 

 the vesiculse, and in others, as the horse, where a communi- 

 cation does exist, the common duct is not of sufficient length to 

 permit the regurgitation of the semen into the vesiculae. 4. Some 

 animals, especially among the carnivora, have no vesicular semi- 

 nales, yet in their copulation they differ not from those which 

 have. M. Richerand indeed asserts, that animals destitute of 

 these organs are longer in coition than others, from having no 

 reservoir for an accumulation of semen.* But he is mistaken. 

 For on inspecting Cuvier's account of animals without and with 

 vesiculae, no connection whatever appears between their presence 

 or absence and the length of copulation. 



In opposition to these arguments it is urged, that a fluid 

 gently propelled along the human vas deferens, does not pass 

 into the urethra, but regurgitates into the vesicula.f But, grant- 

 ing this true, we have no proof that the secretion of the testes 

 leaves the vasa deferentia except during emission, when this regur- 

 gitation is impossible. It may also be contended that, in cases 

 of seminal weakness, the act of straining at the water-closet 

 often instantly discharges from the urethra, without the least 

 sensation, a large quantity of a fluid, which patients, who are 

 of course unprejudiced in favour of any opinion, declare to be 

 exactly similar, in colour, consistence, and odour, to that of a 

 nocturnal emission. The compression cannot squeeze this fluid 

 from the testes. If a partisan of Mr. Hunter should say that 

 the extremities of the vasa deferentia afford it, we may reply to 

 him that Mr. Hunter found them full of the same kind of fluid 

 as the vesicula?. 



* Elemens de Physiologic. Chupitre x. 



t Winslow, Ruysch, Duverney and others, quoted by Hallcr. 



