. ,sm 



SV 



FIG. 159. The yolk of a Hen's egg at, A, the thirty-sixth hour from the beginning of 

 incubation ; B, the third day ; C, the end of the fitth day ; and D, the end of 

 the ninth day (about nat. size). (Compare Fig. 158.) 



ad, area pellucida ; an. inner or " true " amnion ; ,//,-. area opaca ; av. area vasculosa 

 (in C its outer margin) ; a:, outer or " false " amnion (serous membrane) 

 together with the vitelline membrane; cm. embryo: Inn. liymnamlilmlar . I, ft 

 s/i. egg-shell ; sm. vitelline membrane (in c, shall membrane) : TO. an chamber; 

 ta. aliantois ; tea. white or albumen ; y. y*. yolk-sac. (From Marshall.) 



