THE RELATION BETWKKN LIGHT AND PIGMENT-FORMATION. 581 



Table VI. — Showing Effect of Background on the 

 Development of Pigments in young Hippolyte 



VARIANS. 



1908. 



White porcelain vessels with an air- 

 circulatiou. Fine red weed used for 

 food. One vessel covered with a sheet 

 of sfreen glass and two layers of 

 Baker's Sfreeii gelatine giving pure 

 green light. 



1909. 



Large museum jars painted with 

 several coats of flatting, a clear 

 space being left m the front. The 

 red rt'itting reflected red light only, 

 the green flatting reflected green 

 light and a trace of blue Fine red 

 weed WHS used for food. Water- 

 circulation employed. 25 specimens. 



Infer- ' Remarkably pro- On reflectimr 

 ences | tective develop- backgrounds, 

 ment of crimson green !i"'ht 

 I pigment in bright inhibits forma 

 white light ; tion of pig- 

 ments when 

 employed for 

 a short time. 



i left ; all faint 

 green, but re- 

 .'erting to red- 

 lined forms on 

 exposure to 

 dark back- 

 ground 

 Green light 

 suffused Avith 

 bright white 

 light has no 

 distinctive 

 3 'feet. Itmerely 

 acts like dim 

 white light 



Bright 

 reddish-orange 



(2i- 



Red light suf- 

 fused with 

 white light has 

 a definite effect, 

 encouraging 

 the develop- 

 ment of red 

 and yellow 

 pigments. 



VOL, 55, PART 3. NEW SEIHES. 



38 



