626 SPECIAL HISTOLOGY. 



199. Membranes, vessels, and nerves of the testis. The testes, 

 together with their fibrous tunic, and a portion of the epididymis, are 

 immediately invested by the tunica vaginalis propria (Fig. 255, b, d, /), 

 a delicate serous membrane, which, at one time, was a part of the peri- 

 toneum, and corresponds with it in structure. Its epithelium, constituted 

 of a layer 0-005 of a line thick, of clear, polygonal cells, 0-005-0-008 

 of a line in size, with distinct nuclei, and occasionally with isolated, yel- 

 lowish pigment-granules rests on the testis, immediately upon the fibrous 

 membrane, or, at all events, in this situation, is inseparably united with 

 the fibrous coat constituting the tunica adnata testis, or the visceral 

 lamella of the t. v. propria; whilst, on the epididymis, the serous coat 

 may be distinctly separated, and, like its parietal portion, consists of 

 dense connective tissue containing elongated nuclei. The tunica vagi- 

 nalis communis, is a dense, tolerably thick membrane, consisting, on the 

 testis, of firm connective tissue, and higher up, of a more lax reticulated 

 tissue with elastic fibres ; it closely surrounds the tunica vaginalis propria, 

 and also invests the spermatic cord, and the lower end of the epididymis. 

 Between it, the tunica propria, and the e-pididymis, and firmly con- 

 nected with both tissues, is placed a layer of smooth muscles, usually 

 corresponding to the two lower thirds of the testis, the internal mus- 

 cular tunic of the testis ; whilst on its outer side is inserted the cremaster, 

 composed of transversely striated fibres. The scrotum, lastly, is formed 

 by the external muscular tunic of the testis, which is more laxly con- 

 nected with the t. v. communis, the tunica dartos ; with respect to 

 which, vid. 34 ; and by the external integument, which is characterized 

 by its thinness, the absence of fat, the color of its epidermis, and its, 

 mostly, large sebaceous and sweat-glands. 



The bloodvessels of the testis and epididymis are derived from the 

 long and slender a. spermatica interna, which, running in the spermatic 

 cord, proceeds from its posterior aspect to the testis, and sometimes 

 entering at once the corpus Higlimorianum, sometimes divided into nume- 

 rous branches, ramifies in the fibrous tunic of the testis, and on its inner 

 surface, proceeding towards the anterior border of the gland. The 

 coarser ramification in the parenchyma of the testis proceeds partly from 

 the corpus Highmorianum, partly from the points of origin of the septula 

 testis, from the tunica albuginea, into the septula, from which, again, 

 numerous more minute vessels penetrate into the interior of the lobules, 

 constituting a rather wide-meshed plexus of capillaries, 0-003-0-008 of 

 a line in diameter, around the tubuli seminiferi. In the epididymis 



that in the semen of patients who had suffered attacks of double epididymitis, the spermato- 

 zoids remained absent for months, even for years, after a complete restoration of the general 

 health. In some diseases, the spermatozoids themselves are changed. Thus, Lallemand 

 (Annales des Sciences Nat, torn. xv.. p. 30), states, that in patients broken down by seminal 

 losses, they appear imperfectly formed, the tails being rough, irregular, and indistinct. 

 DaC.] 



