DETAILS OF EARLY EMBRYO. 



8 9 



B 



Figs. 72 A E. Transverse sections and details of the blastoderm shown in fig. 72. The sections pass anteriorward from 

 the region of the caudal folds, shown in section A, as far as the "neck" region of the embryo, section E. 



(I. Beginnings of segmental duct. met. Mesoderm. 



ect. Ectoderm at the point where this becomes continuous with the !/. Yollt lying free in the gul cavity. 



mesoderm in the tail folds o( the embryo. ' Urogenilal anlage. 



'"' Enloderm. 



