606 Gideon S. Dodds. 



EXPLANATION OF FIGURES 



18. Side view of anterior portion of embryo of stage 14, showing number and 

 grouping of germ-cells. X 24. 



19 to 34 are drawn to the same scale and were outlined with the aid of a camera 

 lucida. The details of the nucleus are in some cases reconstructed from two 

 adjacent sections. 



19. A single cell from embryo 1 A, as a type of cells of this early stage. X 1260. 



20. A single cell from embryo 2 A, a little older than the preceding. X 1260. 



21. From embryo 6 F. Theearliest recognized germ-cell and some surround- 

 ing cells of the primary entoblast. X 1260. 



22. From embryo 6 D, just a little older than 6 F. This germ-cell lies in the 

 early mesoblast. X 1260. 



