64 COKA D. REEVES 



the fish. They fed a single horned dace, Semotilus atro- 

 maculatus, from forceps, two pairs of which were fastened 

 to a wooden bar so that they could be lowered into the 

 water simultaneously. One pair of the forceps had small 

 red sticks fastened to the legs with rubber bands, while 

 the other was equipped with green sticks. Food was placed 

 in the red forceps to form an association red-food. When 

 the association was formed, both pairs of forceps were 

 presented empty; the fish selected the red, and continued 

 to do so even when a much lighter red was used. 



The conclusion reached by Washburn and Bentley is 

 that the fish can associate food with pigment color and 

 discriminate between red and green even when the shade 

 of the red is changed. 



Reighard (1908) studied color vision in the gray 

 snapper. The primary purpose of his work was the in- 

 vestigation of warning coloration, not of color vision. If 

 the fish upon which he worked should be shown to be color 

 blind, his conclusions that the coloration of coral reef 

 fishes does not serve as warning, would be strengthened. 

 He describes a school of gray snappers (Lutianus griseus) 

 which were fed in the open sea with blue and red bait. 

 The fish showed an instinctive avoidance of red. When 

 they had become accustomed to the feeding, the red bait 

 was presented together with the blue. The fish avoided 

 the red. They also gave preference to white when offered 

 with blue. The brightness of the blue, red, and white 

 were measured by the color wheel and found to be in the 

 order white, red, blue. Professor Reighard concludes that 

 since the snappers preferred the white to the blue, and the 

 blue to the red, they chose in the first case the brighter 

 bait and in the second the duller one of a pair. They were, 

 therefore, guided not by the brightness of the bait but by 

 the color. The quickness and accuracy of the fish in form- 

 ing associations show, in this experiment and in others, the 

 advantage of working with fish in a natural environment. 



Since Zolotnitsky did not determine the relative bright- 

 nesses used by him for either the fish eye or the human 

 eye, it is clear that these may have been such that the fish 

 were able to select the red yarn by its brightness alone. 



