1386 



THE URINO GENITAL ORGANS 



the ejaculatory duct (Fig. 1137). The vas deferens offers a hard and cord-like 

 sensation to the fingers; it is about two feet in length, of cylindrical form, and 

 about 2 mm. in diameter. Its walls are dense, measuring 0.7 mm., and its canal 

 is extremely small, measuring about 0.5 mm. 



Structure. The vas deferens consists of three coats: (1) An external or areolar coat (tunica 

 adventitia). (2) A muscular coat (tunica muscularis), which in the greater part of the tube 

 consists of three layers of unstriped muscle fibre; an inner layer of thin longitudinal fibres 

 (stratum internum), a thick middle layer of circular fibres (stratum medium), and a thick external 

 layer of longitudinal fibres (stratum externum). (3) An internal or mucous coat (tunica mucosa), 

 which is pale, and arranged in longitudinal folds; its epithelial cells are chiefly of the stratified 

 columnar variety of which the superficial layer is ciliated. 



Organ of Giraldes (par ad id y mis). This term is applied to a small body of 

 rounded shape in the lower end of the spermatic cord, in front of the bloodvessels. 

 It consists of a small collection of minute vesicles and a small collection of con- 

 voluted tubules. These tubes are lined with columnar ciliated epithelium, and 

 probably represent the remains of a part of the Wolffian body. 



MUSCULAR 



TUNIC\ 



VAS 

 DEFERENS 



THE SEMINAL VESICLES (VESICULAE SEMINALES) (Figs. 1135, 1136). 



The seminal vesicles are two convoluted membranous pouches placed between 

 the base of the bladder and the rectum, serving as reservoirs for the spermia, and 

 secreting a fluid to be added to the secretion of the testes. Each sac is some- 

 what pyramidal in form, the 

 broad end being directed 

 backward and the narrow 

 end forward toward the 

 prostate. It measures about 

 tw 7 o and a half inches 

 (6.25 cm.) in length, about 

 10 mm. in breadth, and 4 to 

 6 mm. in thickness. They 

 vary, however, in size, not 

 only in different individ- 

 uals, but also in the same 

 individual on the two sides. 

 The anterior surface is in 

 contact with the base of 

 the bladder, extending from 

 near the termination of 

 the ureters to the base of 

 the prostate gland. The 

 posterior surface rests upon 

 the rectum, from which it 

 is separated by the recto- 

 vesical fascia. Their upper 

 extremities diverge from 

 each other. Their lower 



-The urinary bladder, distended, with Surrounding , , . j i 



structures, viewed from behind. (Spalteholz.1 extremities are pointed, and 



converge tow r ard the base 



of the prostate gland, where each joins with the corresponding vas deferens to 

 form the ejaculatory duct. Along the inner margin of each vesicle runs the 

 ampulla of the vas deferens. The inner border of the vesicle and the correspond- 



COWPER'S 

 GLAND 



