THE RELATION IJETWEEN LT(!H'I' AND PIGMENT-FORMATION. 579 



Table IV (1908-9). — Summary of Influence of Light on the 

 Development of Pigments in Hippolyte varians. 



Starting point for these experiments: Small specimens (4^-5^ 

 mm. long), transparent colourless (on black background), 

 faintly red-lined (on white background). Yellow and red 

 chromatophores present, but not in sufficient quantity to give 

 rise to a definite colour (PI. 23, fig. 4). 



