246 THE PHYSIOLOGY OF REPRODUCTION 



retained their desire for copulation although their fertility was 

 diminished. 1 



That the spermatozoa possess complete functional activity before 

 they can be in any way influenced by the secretion of seminal vesicles 

 has been conclusively sho^n by Iwanoff,^ who .induced pregnancy 

 artificially in rabbits, guinea-pigs, and other animals, by injecting 

 into the female passages fluid obtained directly from the epididymis, 

 and mixed with a five per cent, solution of sodium carbonate. The 

 diminished fertility in Steinach's rats, after the removal of the 

 vesiculse, was probably due to the absence of formation of the 

 " bouchon vaginal," as has been suggested by Eauther. 



It would seem probable that, in the majority of animals which' 

 possess vesiculae seminales, the secretion of these glands serves to 

 dilute the semen, and so assists in providing a fluid medium for the 

 transference of the spermatozoa. 



Exner^ has suggested that the seminal vesicles may have the 

 function of absorbing the seminal fluid which is not ejaculated, but 

 there is little evidence that this is the case. 



Lode * found that in castrated bulls, horses, and guinea-pigs the 

 glandular epithelium of the vesicles atrophied, but the connective 

 tissue underwent hyperplasia. Gruber ^ and Pelikann ^ observed that 

 in castrated men the glands atrophied, but became filled with a kind 

 of mucous liquid. 



Steinach^ has shown Ijhat in rats early castration inhibits the 

 development of the vesiculae. Further, castration in the hedgehog 

 done in winter^ prevents the seasonal growth of these glands in the 

 following spring. Unilateral castration, however, has no effect, the 

 vesiculse developing with normal symmetry.^ Vasectomy has also 

 no effect. 



1 If both vesiculse and prostate were removed complete sterility resulted 

 (see below). See also Nussbaum, "Ueber den Bau und die Tatigkeit der 

 Drusen," Arch. f. Mihr. Anat., vol. Ixxx., 1912. 



' Iwanoff, "La Ponctjon des Vesicles seminales et la Glande prostatique,'' 

 Jour, de Phm. et de Path. Gen., vol. ii., 1900. See also papers in C R. de la Soc. 

 de Biol., vols. Ixxiv. to Ixxx., 1913-17. 



^ Bxner, " Physiologie der Mannlichen GescMechtsfunktionen," Frisoh and 

 Zuckenhandl, Handhuch der Urologie, 1903. 



'' Lode, loc. cit. 



^ Gruber, " Untersuchung einiger Organe eines Castraten," Midlers Archiv., 

 1847. 



^ Pelikann, Qerichtl.-mediz. JJnters. ilber d. Shopzentwm, in Russland, Giessen, 

 1876. 



^ Steinach, " Untersuchung zur vergleichenden Physiologie der mannlichen 

 Gesohlechtsorgane," Pflilger's Arch., vol. Ivi., 1894. See also Zent. f. Phys., 

 vol. xxiv., 1910. 



* Marshall, loc. ait. 



