962 GENERATIVE APPARATUS. 



covering this region, and is thin, and so closely adherent to the dartos that it 

 can only with difficulty be separated from it. It is covered by very short fine 

 hair, and the extremely nmnerous sebaceous follicles in its texture secrete an 

 unctuous matter that renders its surface soft to the touch. 



(There are also numerous sudoriparous glands, and these, with the sebaceous 

 glands, keep the skin soft and pUable, and modify the effects of friction during 

 progression. On its surface it shows a 7-aphe or seam in the middle, which is a 

 trace of its primary division, and corresponds to the median septum separating 

 the testicles.) 



2. The Testicles (Figs. 517, 518, 519, 521). 



External Conformation. — Each testicle is oval in shape, flattened on both 

 sides, lodged in the cul-de-sac of the tunica vaginalis,^ and suspended at the 

 extremity of the spermatic cord. The description of this organ is extremely 

 simple ; it offers for study two faces, two borders, and two extremities. 



The faces, external and internal, are smooth and round. The inferior border 

 is convex and free, like the faces ; the supeiHor, ahnost straight, is related to the 

 epididymis, which adheres to it by its head and tail. 



Means of Attachment. — The testicle is freely pendent in the lower part of the 

 tunica vaginalis, where it cannot readily be displaced, because of the narrowness 

 of the space containing it. It is suspended, by its upper border, to the testicular 

 or spermatic cord -."^ a thick funiculus contained in the middle portion of the 

 vaginal sheath, and formed by the aggregation of the spermatic vessels with 

 the vas deferens. 



This cord is itself sustained in the tunica vaginalis by the frsenum that unites 

 the two serous tunics of that cavity. 



Steucture. — Independently of the serous tunic that covers the exterior of 

 the testicle, there enter into its structure a fibrous membrane, tissue proper, and 

 vessels and nerves. The excretory duct will be studied separately. 



Fibrous Membrane. — This membrane, designated the tunica albuginea, forms 

 a strong, resisting, thick shell around the testicle, and its texture is channeled 

 by sinuous spaces which lodge the large spermatic vessels. It is covered by the 

 visceral layer of the tunica vaginalis, to which it closely adheres ; its inner face 

 sends thin septa into the proper substance of the gland, which divide the latter 

 into the spermatic lobules. Towards the upper border of the testicle, and in 

 front, the tunica albuginea is slightly thickened ; this part is named the corpus 

 Higmorianum (or mediastinum testis), and at this point the seminal ducts pass 

 through it to reach the epididymis. 



(This membrane is dense and inelastic, being composed of white fibrous 

 tissue interlacing in every direction.) 



Tissue proper. — The proper substance of the testicle resembles a greyish- 

 yellow pulp, contained in the tunic albuginea ; it is divided by the prolongations 

 which that tunic sends into its interior, into small, conical, distinct lobules {lobuli 



' One or both testicles may be retained in the constricted portion of the tunica va^nalis, 

 or remain in the abdomen ; animals in ■which this occurs are named monorchids or cryptorchids. 

 The absence of one or two testicles (anorchidism) is extremely rare. Ectopix of the testicles 

 is the designation applied to these organs when they are found elsewhere than in the ordinary 

 situation. 



* III surgical anatomy, there is sometimes included in the spermatic cord the middle 

 portion of the tunica vaginalis and ail its envelopes — the serous, fibrous, and erythroid tunics. 



