EJACULATION. 



653 



uterus. According to Litzmann and others, at the time of coitus 

 the uterine muscular tissue contracts, thus compressing the cavity 

 of that organ ; subsequently relaxation occurs and by aspiration, 

 the spermatozoa are drawn into the cavity. Kristeller believes 

 that at the time of the completion of coitus, when the orgasm 

 occurs, the plug of mucus in the cervical canal is forced down into 

 the vagina, and that the spermatozoa, discharged at the same 

 moment, attach themselves to it and are drawn back with it into the 



FIG. 438. Posterior portion of urethra, seen after median incision of the ante- 

 rior wall of the canal ; 1, vesical neck ; 2, section of prostate and urethral sphincters ; 

 3, section of membranous urethra; 4, section of spongy urethra; 4', bulb; 5, 5', cor- 

 pora cavernosa ; 6, verumontanum with orifice of utricle ; 7, posterior wall of 

 prostatic urethra with its glandular openings ; 8, right ejaculatory duct laid bare, 

 with, 8', its opening; 9, Cowper's gland; 10, its excretory duct laid bare; 1CX, 

 opening of this duct; 11, longitudinal fold of mucous membrane of urethra; 12, 

 cul-de-sac of bulb; 13, collar of bulb (Testut). 



uterus. Whether either of these theories is, in the main, the cor- 

 rect one has not been determined. That the spermatozoa can, by 

 the vibratile motion alone of their tails or flagella, penetrate the os 

 uteri is proved by the fact that impregnation has occurred when 

 the woman was unconscious. The rate at which spermatozoa travel 

 in the human female passages is one centimeter in three minutes ; 

 in the rabbit two and three-quarter hours are sufficient for them to 

 reach the ovary. Their vitality is retained in the human passages 



