CH. LIX.] 



THE MALE REPRODUCTIVE ORGANS 



863 



growth of hair on the face and the increase in size of the larynx which 

 leads to the deepening of the pitch of the voice in the male. 



THE MALE REPRODUCTIVE ORGANS 



These consist of the two testes which produce spermatozoa, and 

 the ducts which lead from them. 



The testis is enclosed in a serous membrane called the tunica 

 vaginalis, originally a part of the peritoneum, which descends into the 



FIG. 546. Plan of a vertical 

 section of the testicle, 

 showing the arrangement 

 of the ducts. The true 

 length and diameter of the 

 ducts have been disre- 

 garded, a a, Tubuli semi- 

 niferi coiled up in the 

 separate lobes ; &, tubuli 

 recti ; c, rete testis ; d, vasa 

 efferentia ending in the coni 

 vasculosi ; I, e, g, convo- 

 luted canal of the epidi- 

 dymis; h, vas deferens; 

 /, body of Highmore ; i i, 

 librous processes running 

 between the lobes. 



FIG. 547. Section of the epididymis of 

 a dog. The tube is cut in several 

 places, both transversely and ob- 

 liquely ; it is seen to be lined by a 

 ciliated epithelium, the nuclei of 

 which are well shown, c, Connec- 

 tive tissue. (Schofield.) 



scrotum before the testis and subsequently gets entirely cut off 

 from the remainder of the peritoneum. There are, however, many 

 animals in which the testes remain permanently in the abdomen. 

 The external covering of the testicle itself is a strong fibrous capsule, 

 called, on account of its white appearance, the tunica albuginea. 

 Passing from its inner surface are a number of septa or trabeculae, 

 which divide the organ imperfectly into lobules. On the posterior 

 aspect of the organ the capsule is greatly thickened, and forms a mass 

 of fibrous tissue called the Corpus Highmorianum (body of High- 



