CHAPTER VII 



THE ACCESSOEY REPRODUCTIVE ORGANS OP THE MALE 

 AND THE MECHANISMS CONCERNED IN INSEMINATION 



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

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

 ainsi successivement." — Rabelais. 



A BRIEF description of the mammalian testis has akeady 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 rate testis the spermatozoa, 

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

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

 vasa efEerentia 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 hned 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 epithehum, which is 

 not ciliated.! 



' 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 Wolffian body, are called the paradidymis or organ of 



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



with the process of ejaculation. 



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