PLATE 6 



Figs. 10, 11 and 12. Early stage in the development of a yellow pigment 

 cell from the larva of Hyla. A few minutes after figure 10 was sketched 

 the cell had assumed the form shown in figure 11. Figure 12 shows the 

 contracted state assumed after the application of heat. 



Fig. 13. A yellow pigment cell from a larva of Dicmyctybis. 



Fig. 14. Two leueophores from the ventral side of a young larva of 

 Diemyctylus. 



Fig. 15. Connective tissue cell from the tail of a larva of Diemyctylus. 

 The cells shown in figs. 9, 13, 14 and 15 were not isolated from the sur- 

 rounding tissues. 



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