332 



A. 



THE MAMMALIAN EMBRYO. 



Fig. 107. 



B. 



[chap. 



Transverse Section through the Head of a Eabbit of 

 THE same age as Fig. 106 B. (From KoUiker.) 



B. is a more highly magnified representation of part of A. 



rf. medullary groove ; Trip, medullary plate ; rw. medullary fold ; 

 h. epiblast ; dd. hypoblast ; dd! . notochordal thickening of 

 hypoblast ; sp. undivided mesoblast; hp. somatic mesoblast; 



