420 



THE EVOLUTION OF MAN, 



naculum testis) (Fig. 328, M, gh) ; in the female, the round 

 uterus-cord (Fig. 328, F,t). In the latter the ovaries 

 migrate more or less in the direction of the small pelvis, or 



^A.. 



. 9h 



n- A 



Fig. 328, M. 



Fig. 328, F. 



Fig. 328. — Original position of the sexual glands in the abdominal cavity 

 of the human embryo (of three months). Fig. 328, M, male (natural size) : 

 h, testis ; gh, the conducting-cord of the testis ; wg, seed-duct ; h, urinary 

 bladder ; uh, lower hollow vein (vena ca/od) ; nn, supplementary kidneys ; 

 n, kidneys. Fig. 328 F, female (somewhat enlarged) : r, I'ound uterus-cord 

 (below this the urine-bladder, above it the ovary) ; r', kidney ; s, sup- 

 plementary kidney ; c, blind-intestine {caecum) ; o, small net ; om, large 

 net (between the two is the stomach) ; Z, spleen. (After Kolliker.) 



even enter this. In the male the testis quits the abdominaj 

 cavity altogether, passing through the groin-canal, and 

 enters a sac-shaped, distended fold of the external skin- 

 covering. The coalescence of the right and left folds 

 (" sexual folds ") gives rise to the testis-sac {scrotum).. The 

 various Mammals exhibit the various stages of this migra- 

 tion. In the Elephant and in Whales the testes descend 

 very little, and lie below the kidneys. In many Gnawing- 

 Animals (Rodentia) and Beasts of Prey (Carnaria) they 

 enter the groin-canal. In most higher Mammals they pass 

 down through this into the testis-sac ; usually the walls of 



