630 



REPRODUCTIVE ORGANS. 



the testes, vasa deferentia, vesiculse seminales, prostate, Cowper's 

 glands, and the muciparous glands of the urethra. It is whitish 

 in color, viscid in consistency, alkaline in reaction, and possesses 

 a characteristic odor. The amount ejaculated varies from 0.5 c.c. 

 to 6 c.c. It contains from 82 to 90 per cent, of water, imclein, 

 protamin, proteids, xanthin, lecithin, cholesterin, fat, sodium and 

 potassium chlorids, sulphates, and phosphates. From it may be 

 obtained Charcot's crystals, which are a phosphate of the nitrogen- 

 ous base, spermin, and which have 

 their origin in the portion of the 

 semen which is contributed by the 

 prostate ; to the decomposition of 

 the substance which produces these 

 crystals the odor of the semen is at- 

 tributable. While the spermatozoa 

 are the essential fertilizing agents, 

 the presence of the fluid portion of 

 the semen is important as giving to 

 them their mobility, without which 

 they could not travel in the genera- 

 tive passages. 



Penis (Fig. 411). The penis 

 serves a double purpose, inasmuch 

 as it is the organ of copulation and 

 also the termination of the urinary 

 passages. The former function is 

 undoubtedly the essential one, for 

 there is no reason why the urinary 

 passages could not terminate at the 

 surface of the body ; it is, however, 

 manifestly advantageous in provid- 

 ing for the perpetuation of the spe- 

 cies that the semen should be ex- 

 pelled as near as possible to the 

 mouth of the uterus, a result which 

 is obtained by the intromission of 

 the penis. 



The penis consists of erectile 

 tissue arranged in three subdi- 

 visions, two above, corpora cavernosa, and one below, corpus 

 spongiosum, which latter terminates in the glans penis. The 

 corpora cavernosa are surrounded by fibro-elastic sheaths from 

 which are given off trabeculce. These pass inward, and between 

 them are spaces which contain venous blood. A similar structure 

 characterizes the corpus spongiosum which encloses the urethra. 



The arteries which supply the penis are derived from the 

 internal pudic (Fig. 413). Sensory nerves are distributed to the 



FIG. 412. Sagittal section of the 

 anterior extremity of the penis : 1, 

 glans penis ; 2, corpus cavernosum ; 

 3, 3, spongy portion of urethra; 4, 

 meatus urinarius; 5, fossa navicularis ; 



6, left half of the valve of Guerin ; 



7, sinus of Guerin between the valve 

 and the anterior wall of the urethra ; 



8, left lateral border of urethra: 9, 

 its lower surface ; 10, prepuce pushed 

 back behind the glans; 11, frenum ; 

 12, integument ; 13, dorsal vein ; 14, 

 fibrous partition between the corpus 

 cavernosum and corpus spongiosum 

 (Testut). 



