98 K. KISHIXOUYE. 



Plate VII. 



Fig. 21. Transverse section through the blastodermic thickening of an egg, 



10 days old, shown in fig. 3. 2C. 



Fig. 22. Transverse section througli the blastodermic thickening of an egg, 



11 days old. 2B. 



Fig. 23. Transverse' section through the rudimentary ventral plate of an egg, 



13 days old, showing the separation of the blastodermic thickening into 



epiblast and mesoblast. 2B. 

 Fig. 24. Portion of a section, similar as above, showing the columnar epiblast 



cells and a mesoblast cell wilh 2 very large nuclei. 2D. 

 Fig. 25. Transverse section through the cephalic lobe of an embryo, 1-i days old 



(fig. 5), showing the separation of the mesoblast into 2 lateral bands. 2B. 

 Fig. 26. Longitudinal section through the ventral plate of an embryo, 10 days 



old (fig. 8), showing the appearance of the cœlomic cavity in the 5th 



segment. 2B. 

 Fig. 27. Transverse section through the primitive streak of an embryo, 10 days 



old (figs. 8,9), showing the formation of the mesoblast cells in the 



posterior part of the ventral plate. 2D. 

 Figs. 28-31. Transverse sections througli the ventral plate of an embryo, 17 days 



old (fig. 10). 2B. 

 Fi". 82. Transverse section through the posterior part of the ventral plate of an 



embryo, about 20 days old (fig. 14). 2B. 

 Fig. 33. Transverse section of the anterior part of an embryo, shown in fig. 



12. 2B. 



Plate VIII. 



Fi"s. 3-4, 35. Horizontal sections of the cephalic region of an embryo, shown in 



fig. 12. 2C. 

 Figs. 36, 37. Horizontal sections of the cephalic region of an embryo, shown in 



fig. 13. 2C. 

 Fig. 38. Horizontal section of the cephalic region of an embryo, shown in fig. 



14. 2C. 



