THE RELATION BERVVEEN A MITOSIS AND MITOSIS. 



I I I 



are contained in the egg-cell itself. The first yolk granules to 

 appear, however, are not confined to this region but are more or 

 less scattered (Fig. 24). The natural conclusion from the 

 sequence of events is that the change in nuclear condition is in 

 some way correlated with the cytoplasmic changes and since the 

 former precedes, that it is in some way responsible for the latter. 

 Nuclear changes connected with yolk-formation have been de- 



24 



FIGS. 24, 25, 26, 27, 28. 



scribed by many authors but it is necessary to review the various 

 accounts. It seems probable these nuclear changes indicate an 

 alteration in the metabolic processes and that they are concerned 

 primarily with the increase of the cytoplasm and the deposition 

 of yolk. 



Figs. 24-27 show successive stages in yolk-formation. The 

 granules formed first increase in size and others appear. Fusion 



