836 ORGANS OF REPRODUCTION. 



The prostate gland surrounds the neck of the bladder and commence- 

 ment of the urethra (Fig. 211). It secretes a milky fluid, which is con- 

 veyed by the prostatic ducts to the floor of the urethra. Cowper's glands 

 are two small glands which are situated between the layers of the deep 

 perineal fascia at the anterior part of the membranous urethra. They 

 secrete a viscid fluid, which is conveyed by ducts to the floor of the 

 urethra. 



The testes or testicles are two small, flattened, ovoidal glands, which are 

 situated in a musculo-inembranous pouch, called the scrotum, and suspended 

 by the spermatic cords. Each testicle consists of two parts : the gland 

 proper and the epididymis. The gland (Fig. 213) is composed of an outer 



FIG. 211. 



i 



View of a Section of Prepared Ovary of the Cat. (After Schron.) X 6. 1, outer covering and 

 free border of the ovary ; 1', attached border ; 2, the ovarian stroma, presenting a fibrous and 

 vascular structure ; 3, granular substance lying external to the fibrous stroma ; 4, bloodvessels ; 

 5, ovigerms in their earliest stages occupying a part of the granular layer near the surface ; 6, 

 ovigerms which have begun to enlarge and to pass more deeply into the ovary ; 7, ovigerms 

 round which the Graafian follicle and tunica granulosa are now formed, and which have passed 

 somewhat deeper into the ovary and are surrounded by the fibrous stroma ; 8, more advanced 

 Graafian follicle with the ovum imbedded in the layer of cells constituting the proligerous disc ; 

 9, the most advanced follicle containing the ovum ; 9', a follicle from which the ovum has acci- 

 dentally escaped ; 10, corpus luteum. 



fibrous coat, the tunica albuginea, this being covered by a serous membrane, 

 the tunica vaginalis. The substance of the gland consists of a number of 

 pyramidal lobular divisions, which are situated with their bases toward the 

 surface. Each lobule is composed of several convoluted tubuli seminiferi, 

 and are separated from adjoining lobules by prolongation of fibrous tissue 

 from the tunica albuginea. The tubules are composed of a homogeneous 

 basement membrane, which is lined by granular nucleated epithelium. In 

 the apices of the lobules they have a straight course, and form the vasa recta. 

 They then enter the fibrous tissue of the mediastinum (Fig. 213), and form 

 a plexus of tubes called the rete testis, which end in the upper part of the 

 mediastinum as the vasa efferentia, and these becoming very much convoluted 

 from the globus major or head of the epididymis. The tubules of the globus 

 major unite to form a single tube, which is Very much convoluted, and con- 

 stitutes the body and globus minor of the epididymis, and is then continued 

 from the globus minor to the base of the bladder as the excretory duct or 

 vas deferens. 



The vas deferens, commencing at the globus minor, ascends in the pos- 

 terior part of the spermatic cord through the spermatic canal into the pelvis, 

 where it runs to the base of the bladder and becomes enlarged, sacculated, 



