338 HARRY H. CHARLTON. 



PLATE IV. 



FIG. 15. Drawing of adjacent section to that shown in Fig. 14. 



FIG. 16. (72 hours.) Egg showing the formation of protoplasmic fragments 

 independent of any spindle. These are later pinched off and form small segments 

 inside the zona. 



FIG. 17. Drawing of adjacent section to that shown in Fig. 16. A study of 

 all the sections of this egg shows that seven fragments have been pinched off, 

 and that of these only two appear to contain nuclear material. 



FIG. 18. (105 hours.) Egg is without zona, contains two nuclei and two 

 immensely large refractive mitochondrial bodies. The polar body still remains 

 attached to the egg. 



FIG. 19. An 8i-hour egg showing phagocytic effect. In two upper cells the 

 mitochondrial bodies have been pulled out of the cytoplasm towards the left by 

 the knife, leaving clear spaces where they originally were, indicating the solid 

 character of these structures. Many vacuoles are seen around the border of the 

 fragments. Between the cells dark stained particles of degenerated cytoplasm is 

 being absorbed by the phagocytes. 



FIG. 20. (81 hours.) A later stage than Fig. 19. In one of the fragments 

 hardly any content is to be seen except a few scattered granules. 



