214 



G. E. COGHILL 



Figs. 15, 16, 17 From an embryo of the non-motile stage, between the thir- 

 teenth and fourteenth myotomes. Same fixation and staining as figure 7. Trans- 

 verse plane; 5 n. 



Fig. 18 From a non-motile embryo, at the level between the ninth and tenth 

 myotomes. Fixation in formalin-Zenker; Delafield's hematoxylin and acidulated 

 orange G; horizontal plane; 10 yu. 



