220 



Edmund B. JVilson. 



Fig. VI. 



Isolated i^ Cells and Isolated First Quartet, Patella. 

 (Fig-s. 58-62, 65, 66 X 250; Figs. 63, 64 X 290). 



58, isolated iM 59, 60, two examples of first division (rosette-cell slightly 

 too large in both); 61, 62, two examples of second division; C>3, product, 12 

 hours, apical cells and secondary trochoblasts (somewhat smaller cells on re- 

 verse side); 64, similar larva of 22 hours; 65, first division of isolated first quar- 

 tet; 66, second division; 67, product, 24 hours. (Some of the cells have been 

 lost). 



