230 MANUAL OF HISTOLOGY. 



The glandular structure, together with the epididymis of the 

 testicles, is enveloped by a dense fibrous membrane, the tunica 

 albuginea. This is surrounded by a serous sac, the tunica 

 vaginalis propria. Finally the testicle and spermatic cord are 

 invested by the tunica vaginalis communis and the whole is 

 contained in the scrotum. 



The tunica albuginea upon its external surface, or that 

 covered by the tunica vaginalis propria, is smooth and shin- 

 ing ; it consists of dense connective tissue with some elastic 

 fibres ; upon the posterior border of the testicle it increases in 

 thickness, and is here termed the corpus Higlimori, or medias- 

 tinum testis, which passes into the gland. It also sends off 

 from its whole internal surface numerous bands or trabeculse, 

 the septula testis, which run toward the mediastinum, and 

 divide the .interior of the testicle into conical lobules, having 

 their apices directed toward the corpus Higlimori. These tra- 

 beculse contain smooth muscular fibres and blood-vessels. It 

 is in these lobules or spaces that the secreting elements of the 

 gland are situated. 



The serous sac, or tunica vaginalis, has its visceral la}^er, the 

 tunica adnata, intimately united to the tunica albuginea over 

 the testicle, but it is loosely attached to that over the epididy- 

 mis. This membrane consists of connective tissue traversed 

 by delicate elastic fibres, and lined on its surface with a layer 

 of polyhedral cells, varying in size and containing oval nuclei 

 with one or two nucleoli. Upon the upper portion of the tes- 

 ticle and sharp edge of the epididymis, the tunica adnata is 

 frequently found to possess tufted excrescences ; these pro- 

 cesses are covered by several layers of flattened epithelial cells, 

 or a single layer of round or cylindrical -bodies. A capillary 

 loop is seen extending into the tufts. 



The parietal layer of the tunica vaginalis propria consists 

 of connective tissue, elastic fibres, and epithelium, as in the 

 visceral layer. 



The tunica vaginalis communis, which covers the tunica 

 vaginalis propria, is composed above of a loose, laminated con- 

 nective tissue, but it becomes more dense below. Between 

 this tunica and the tunica propria unstriped muscular fibres 

 are found, while upon its external surface there are the striped 

 fibres of the cremaster muscle. Small non-vascular peduncu- 

 lated excrescences are also found upon this surface. The mem- 



