DEVELOPMENT OF BIMAXA. 



747 



but in the Chimpanzee the placenta is single. In all old-world 

 Quadrumana the umbilical vein is single, as in Bimana. Where 

 any trace of vitellicle has been detected in Quadrumana, it has 

 been very small. 



§ 406. Development of Bimana. — The lining substance of the 



580 



Impregnated uterus, placenta and foetus, Cercopilhecus sabaus. cclxxvii' 



human uterus, when an ovum is impregnated, augments in thick- 

 ness, fig. 570, and seems to degenerate into a pulpy spongy mass, 

 into which the ovum sinks on entering the womb : its position is 

 shown, diagrammatically, in fig. 572, b, e : but the special chamber 

 in which, at first, it lies loosely, is exhibited in fig. 581 : here, 

 bristles are introduced at the orifices corresponding with those of 

 the oviducts, and pass out at the beginning of the cervix uteri, 



