DETAILS OF EARLY EMBRYO. 



8l 



ft 



B 



Figs. 71 A-E and continued F-I on page 82. Transverse sections of late gastrula shown in Plate V, fig. 36. The sections pass 

 forward; the first of the series. A, traverses the tail folds; the last, I, ihe head region of the early embryo. 



" Tongue of mesoblast cells representing the urogcnital anlage ; b* mcgaspherci in process of passing through the yolk-enlobUsI ; 6c, body cavity; 

 <\ points in extra -embryonic region where the ectoderm celti are being proliferated into the blastoderm ; </t gut cavity ; in, megupherr appearing 

 in periitomtal mesoblast. 



