1 2 3 4 5 



Fig, 3-14. Photomicrographs of melanophores from the wch of 

 the foot of the clawed toad, Xenopus laevis, with pigment in 

 progressive stages of dispersion corresponding to the melanophorc 

 indices 1 to 5. Values such as 15 are sometimes recorded directly; 

 but they usually represent the mean of several readings (from 

 Hogben and Slome, 1931) 



Fig. 3-18. Photomicrographs of chromatophores exposed by remov- 

 ing a scale mid-dorsally from the killifish , Fundidus. {a) Black-adapted 

 with melanophores dispersed and showing iridosomes at the centre 

 of some ; guanophores are concentrated and xanthophores appear 

 grey, {b) The same after injection of adrenaline. The melanophores 

 are concentrated, and the guanophores widely dispersed as they 

 would be in a light-adapted specimen (from Odiorne, 1933). 



