86 



BIOLOGICAL LECTURES. 



Finally, I shall describe a few subdivisions of the first and 

 second quartettes with reference to these cell movements. 

 During and after the formation of the first quartette, the rota- 

 tions in these cells are dexiotropic ; when the nuclei have been 



Fig. 13. 



Fig. 14. 



Figs. 13 and 14. — Entire eggs of C . plana. Fig. 13, Unequal division of first quartette cells. 

 Fig. 14, Subdivision of second quartette cells and fornialiou of third quartette. 



