292 Records of the Indian Museum. [Vol. XIII, 1917.] 



The yellow and red lipochromes occurring in the tadpoles are 

 not essentially different, though alcoholic solutions of them may 

 appear quite separate. 



Like the black chromatophores, the coloured ones are modi- 

 fications of special connective tissue cells in which the pigments 

 are deposited. Cells which have undergone such a change appear 

 scaly and if the scale should break, as sometimes happens in the 

 course of preparing tissues for mounting, the pigment occurs in 

 the form of granules. Such a process must naturally take place in 

 the subcutaneous tissues. Similarly the cells which develop gua- 

 nin granules in the protoplasmic contents become transformed 

 into iridocytes. They are easily marked off from the other tissue 

 cells by their shape, — more or less flask-like, and the fact that 

 they are not stained. As metamorphosis progresses, large amoe- 

 bacytes make their appearance wherever iridocytes and argenteum 

 occur (fig. 13). 



