The principal organs which subserve the function of reproduction in the male are: (1) the testis, (2) the excretory ducts which convey the spermatic fluid to the urethra, (3) the urethra, (4) the penis.

The testis in the foetus first appears behind the kidneys (see Plate XXXIV) on the under surface of the loins, from which it hangs suspended in a pouch of peritoneum (the mesorchium). At this time it is connected with the scrotum by a band of unstriated muscle (gubernaculum testis), the gradual contraction of which draws the organ through the inguinal canal into the scrotum or purse, which it reaches about the time of birth.