236 THE PHYSIOLOGY OF REPRODUCTION 



pudio arteries. The veins communicate with the dorsal vein 

 of the penis and with the internal ihac vein. The innervation 

 of the gland is described below in deaUng with the mechanism 

 of ejaculation (p. 258). 



The prostatic secretion is a viscid, sHghtly acid Hquid 

 (sometimes neutral or even alkaUne), containing proteins 

 and salts. ^ (See p. 287.) The characteristic smell of the 

 ejected seminal fluid is said to be partly due to the prostate 

 secretion, which also contributes to the formation of Bottcher's 

 crystals described below (p. 285). 



De Bonis ^ describes the epithelial cells of the dog's prostate 

 as containing a small number of granules. When these have 

 been formed in sufficient quantity, so as almost to fill the cell, 

 its wall ruptures and the granules pass out into the lumen of 

 the gland. This occurs especially during coitus. After the dis- 

 charge of the granules fresh ones are formed in the cells of the 

 gland. 



Little is definitely known regarding the function of the 

 prostate beyond the fact that it contributes additional fluid to 

 the semen. It may, perhaps, assist in providing the spermatozoa 

 with nutriment.^ There is some evidence, however, that it 

 exercises a stimulating influence upon the movements of the 

 spermatozoa.* Steinach observed that prostatic fluid, when 

 added to normal sahne solution, kept the spermatozoa in active 

 movement for a longer period than sahne solution alone. 

 Steinach also found that rats in which the prostate gland, 

 together with the seminal vesicles, was extirpated, were ab- 

 solutely sterile,^ but this may have been due to failure to form 

 a " bouchon vaginal " in the female. As already mentioned 



* Poehl, Die Physiol.-chem. Orundlage der Spermintheorie, St. Petersburg, 

 1898 ; Fiirbringer, Die Storungen der Geschlechtsfunktion des Marines, 

 Wien, 1895 ; Berliner klin. Wochenschrifi, vol. xxiii., 1886. 



2 De Bonis, " tjber die Sekretionserscheinungen in den Drusenzellen der 

 Prostata," Arch. f. Anat. u. Phys., Anat. Abth., 1907. 



' It has been suggested also that the prostate is a sphincter of the 

 bladder, but this is rendered unlikely by its absence in the female. It is more 

 probable that it serves to cleanse the urethra of urine before copulation. 



^ Fiirbringer, loc. cit. Kolliker, "Physiologische Studien uber die Samen- 

 fliissigkeit," Zeitschr. f. wiss. Zool., vol. vii., 1856. 



5 Extirpation of the vesiculse seminales alone produced only partial 

 sterility (see p. 234). 



