PR O TO PL A SMIC MO VEMENT. 



FIG. g. 



FIG. 10. 



FIGS. 9 AND 10. Entire eggs of C. piano. ; third cleavage. Sphere substance of second cleavage 

 at central and upper angles of cells. Initial direction of the spindles not uniform. 



preceding cleavage. The protoplasmic area increases with the 

 breaking of the nuclear membrane, and the spindles do not 

 occupy similar positions in the four cells but are often dexio- 



