CHAPTER VII 



THE ACCESSORY REPRODUCTIVE ORGANS OF THE MALE 

 AND THE MECHANISMS CONCERNED IN INSEMINATION 



" Mais, par ce moyen de propagation seininale, demeure es enfans ce 

 qu'estoit de perdu es parens et es nepveux ce que de"perissoit es enfans, et 

 ainsi successivement." RABELAIS. 



A BRIEF description of the mammalian testis has already been 

 given in a chapter on the physiology of the spermatozoon 

 (p. 166). It remains, however, to state what is known regarding 

 the functional relations of the accessory male organs, and to 

 refer incidentally to the homologous structures in the female. 



After traversing the tubules of the rete testis the spermatozoa, 

 swimming in the seminal fluid, make their way into the vasa 

 efferentia, which open into the canal of the epididymis. The 

 vasa efferentia in Man are about twenty in number. Before 

 passing into the epididymis they become convoluted, forming 

 the coni vasculosi. Both the vasa efferentia and the tube of 

 the epididymis contain smooth muscular fibres in their walls. 

 They are lined internally by columnar epithelial cells provided 

 with long cilia, which assist the muscles in expelling the semen. 



Passing away from the epididymis, and in continuation with 

 its canal, is the vas deferens, which is nearly two feet long in 

 the human subject, and has an average diameter of about one- 

 tenth of an inch. It possesses a plain muscular wall, consisting 

 of an outer layer of longitudinal, a middle of circular, and an 

 inner of longitudinal muscles. On the inside of the muscles 

 there is a mucous coat lined by a columnar epithelium, which is 

 not ciliated. 1 



1 Arising from the lower part of the epididymis, or from the vas deferens 

 close to its commencement, is a long narrow diverticulum which ends blindly. 

 This is the vas aberrans. It is probably a vestigial structure. A few small 

 convoluted tubes, situated near the head of the epididymis and representing 

 vestiges of part of the Wolftian body, are called the paradidymis or organ of 

 Giraldes. The innervation of the vas deferens is described below in dealing 

 with the process of ejaculation. 



227 



