232 THE PHYSIOLOGY OF REPRODUCTION 



testicular end of the vas deferens, they first enter the seminal 

 vesicle and afterwards pass out through the urethra. He 

 concludes that the vesiculae serve the double purpose of secretory 

 glands and reservoirs for the semen. Misuraca l states that 

 in dogs and cats, which have no seminal vesicles, 2 the sper- 

 matozoa disappear from the male passages from five to seven days 

 after castration, whereas in guinea-pigs, in which the vesicles 

 are well developed, sperms may be found alive as long as twenty 

 days after the removal of the testes. This is regarded as 

 evidence that the seminal vesicles function as receptacles for 

 the spermatozoa. Moreover, Meckel 3 stated that he found 

 sperms in the vesiculae of the mole in the month of February 

 (i.e. during the breeding season) ; and Seubert 4 recorded a 

 similar observation about the hedgehog in August (also in the 

 breeding season) (cf. p. 60). Disselhorst, 5 however, throws 

 some doubt on these observations. That the vesiculae may 

 undergo periodic enlargement in animals which have a rutting 

 season is, however, an unquestionable fact. 



As evidence that the vesiculae seminales are undoubtedly 

 secretory glands, Lode 6 showed that in young animals, in which 

 one of the testes had been removed, the corresponding vesicula 

 continued to grow, and became filled with its characteristic 

 fluid. It was evident, therefore, that the fluid must have been 

 secreted in the vesicula in question, since it could not have 

 been derived from the testis of the other side. (The effects 

 of complete castration on the growth and activity of the vesi- 

 culae seminales are briefly referred to below.) Stilling 7 and 



1 Misuraca, " Sopra un importante questione relativa alia castrazione," 

 Rimata sperimentale di Freniatria, vol. xv., 1890. 



2 Seminal vesicles are absent not only in dogs and cats, but in raany other 

 Carnivora, and also in Cetacea and Ruminantia. They are also wanting in 

 rabbits, but are present in the vast majority of Rodentia (Owen, Comparative 

 Anatomy, vol. iii., London, 1868). 



3 Meckel, Beitrage zur Vergleichende Anatomie : I. Ueber die M&nnlichen 

 jleschlechtsteile des Maulwurfs, 1809. 



4 Seubert, " Symbolum ad Erinacei europsei anatomen," Inaug. Dissert., 

 Bonn, 1841. 



5 Disselhorst, loc. cit. 



* Lode, " Experimentelle Beitriige zur Physiologic der Samenblasen," 

 Sitzungsber. d. kais. Acad. d. Wissenschaft in Wien, vol. civ., 1895. 



7 Stilling, " Beobachtungen liber die Functionen der Prostata und liber die 

 Entstehungenprostatischer Concremente," Virchow'g Archiv, vol.xcviii., 1884. 



