552 



OF SECRETION. 



a. The Testis in Man has in every respect, however, a distinctly glandular character. 

 It consists of several lobules, which are separated from each other by processes of the 

 tunica albuginea that pass down between them, and also by an extremely delicate mem- 

 brane (described by Sir A. Cooper under the name of tunica vasculosa) consisting of 

 minute ramifications of the spermatic vessels united by areolar tissue. Each lobule is 

 composed of a mass of convoluted Tubuli Seminiferi, throughout which blood-vessels 

 are minutely distributed. The lobules differ greatly in size, some containing one, and 

 others many of the tubuli; the total number of the lobules is estimated at about 450 in 

 each testis, and that of the tubuli at 840. The convolutions of the tubuli are so arranged, 

 that each lobule forms a sort of cone, the apex of which is directed towards the Rete 

 Testis. It is difficult to trace the free extremities of the Seminiferous tubes, owing to 



[Fig. 163. 



[Fig. 164. 



The Testicle injected with mercury; 1, tunica 

 albuginea; 2, seminiferous tubes; 3, the rete vas- 

 culosum testis ; 4, a globule of mercury which has 

 ruptured the tubes; 5, the vasa efferentia which 

 form the coni vasculosi ; 6, coni vasculosi forming 

 the head of the epididymis ; 7, epididymis ; 8, glo- 

 bus minor of the epididymis ; 9, vas deferens.] 



A view of the minute structure of the Testis; 

 1, 1, tunica albuginea; 2, 2, corpus highmorianum; 

 3, 3, tubuli seminiferi convoluted into lobules ; 4, 

 vasa recta ; 5, rete testis ; 6, vasa efferentia ; 7, coni 

 vasculosi constituting the globus major of the epi- 

 didymis ; 8, body of the epididymis ; 9, its globus 

 minor; 10, vas deferens ; 11, vasculum aberrans or 

 blind duct.] 



the frequency of their anastomoses with each other; in this respect, therefore, the 

 structure of the testis accords closely with that of the Kidney. The diameter of the 

 Tubuli is for the most part very uniform; in the natural condition they seem to vary 

 from about the T ^th to the T 4<y*th of an inch ; but when injected with mercury they are 

 distended to a size nearly double the smaller of these dimensions. When they have 

 reached to within a line or two of the Rete Testis, they cease to be convoluted, several 

 unite together into tubes of larger diameter, and these enter the rete testis under the 

 name of tubuli redi. The rete testis consists of from seven to thirteen vessels, which run 

 in a waving course, anastomose with each other, and again divide, being all connected 

 together. The vasa efferentia which pass to the head of the epididymis are at first 

 straight, but soon become convoluted, each forming a sort of cone, of which the apex is 

 directed towards the rete testis, the base to the head of the epididymis. The number of 

 these is stated to vary from nine to thirty; and their length to be about eight inches. The 

 epididymis itself consists of a very convoluted canal, the length of which is about 

 twenty-one feet. Into its lower extremity, that is, the angle which it makes where it ter- 

 minates in the vas deferens, is poured the secretion of the vasculum aberrans or appen- 

 dix; which seems like a testis in miniature, closely resembling a single lobule in its 

 structure. Its special function is unknown. 

 b. The Testicles originate in the Embryo, from the lower part of the Corpora Wolffiana 



