EXPLANATION OF PLATE 10 



All of the figures were drawn to the same scale and represent isolated pig- 

 ment cells from the frog Sana pipiens. 



Figs. 1-5. Various forms of the larger pigment cells that became isolated 

 in the culture medium. 



Figs. 6, 7 and 8 were taken at different times from the same cell. 



Figs. 9-14 represent successive changes in form of a single cell within a 

 half hour. 



[174] 



