REPRODUCTION 



389 



position in the body more or less comparable with that of 

 the ovaries in the female, but about the time of birth they 

 descend into a double pouch, the scrotum, suspended from 

 the perineum ("crotch"). From the period of sexual 

 maturity onward to old age they produce spermatozoa in 

 prodigious numbers. These find their way through coiled 



FIG. 81. A diagram of the male genitalia. The section is somewhat to 

 the left of the mid-plane. T is the left testis. The spermatozoa are 

 conveyed along the course indicated by the arrows. So they reach the 

 (left) seminal vesicle V at the base of the bladder B. The channel pro- 

 vided for their discharge, the urethra, is dotted. R is the rectum. 



passages of minute diameter and incredible length to a pair 

 of contractile containers, the seminal vesicles, on the under 

 surface of the bladder. During the height of sexual excite- 

 ment the seminal vesicles are thrown into rhythmic con- 

 tractions and the spermatozoa, borne in a complex secre- 

 tion, are forced out by way of the urethra, the channel 

 ordinarily serving to discharge the urine. 



The male urethra extends the length of the penis. This 

 organ is described as intromittent in function; that is, when 



