Figure 9, which is from an embryo only 24- hours older than that shown in Figure 8, 

 exhibits an almost total disappearance of the yolk granules, and a concomitant 

 increase in the amount of the cytoplasm of the myosyncytium. At points e. 

 and g. achromatic yolk granules are shown. These granules are attacked by 

 some new potent substance, which digests them. They then blend with the 

 general myosyncytium, but part of the resulting material is ingested by the 

 nuclei, which in consequence become enormously turgid (see Figures 2, 3, 5, 6 

 and 7). At points a. b. c. and d. the very earliest phases of formation of the 

 muscle fibrils can be seen. X 1000. 



Sec. IV, 7 B 



