DETAILS OF EARLY EMBRYO. 



93 



/ 



Figs. 73 A S.-Transverse sections ot embryo shown in plate V, fig. 38, and in plate VI, figs. 41 and 41 A. These begin at the 

 head end of the embryo, section A, and extend through 47 sections to the tip ot the tail, section UU (see pages 94 and 95.) 

 i/» Gul cavity ; '^, nolochord; ■*» somite. 



