COLOR AND THE BEHAVIOR OF ARTHROPODS 



81 



20 cm. in height, and their other dimensions were 12 cm. and 

 15 cm. respectively; they were kept about one-fourth full of 

 filtered water, which was changed frequently. Each of the six 

 jars was, except at the top, completely enclosed within a tightly 

 fitting wooden box (called a "color box" in these experiments) 

 which had been painted a particuliar color on the inside. One 

 box was painted black and another white ; the colors used in the 

 others corresponded to the following shades in Klingksiegk et 

 Valette's "code des couleurs":* Red, 8; yellow, 128; green, 303; 

 blue, 376. A cardboard painted like the inside of the box was 

 supported three-quarters of an inch above each in such a way 

 that though ventilation was permitted and light allowed to 

 enter, the color environment of the crayfishes in each jar was 

 all of one shade. Figure i is intended to represent the general 

 plan of a color box. 



a'pg' 



Figure 1 — Showing plan of a "color box" containing a glass jar 



partly full of water. , 



The crayfishes were placed in the color boxes on December 10, 

 1908, and kept under observation until January 19, 1909. During 

 this time most of the individuals gradually changed color slightly 



*Ivlingksiegk et Valette's Code des couleurs will be subsequently indicated by 

 the initials, C. C. 



