PR O TOP LA SMIC MO I 'EMENT. 



79 



b. Movements einring Cleavage. 



It is, however, in the cleavage cells that I have found the 

 most unmistakable evidences of the definite and orderly move- 

 ments of cell contents. In the first cleavage the spindle lies at 



•vQ: 



'■'-'-■'• '''o%^Ar:^\:>i3M 



Fig. 3. 



C) :•". : ■..*.•• 



CPdm 



Figs. 3 and 4. - 



'o 



Fig. 4. 



• Sections of eggs of C. plajia, showing anaphase and telephase 

 of first cleavage. 



og. 



Wi'G 



right angles to the chief axis of the ^g%, and the centrosomes 

 are no nearer the surface of the Q.gg than is the middle of the 

 spindle (Figs. 1-3). As the daughter-nuclei pass into the rest- 

 ing phase, however, the centrosomes are transformed into cen- 



