ASSOCIATION AND COLOR DISCRIMINATION 449 



Goldsmith ('12) arranged aquaria with colored bottoms. 

 Young plaice preferred red to any other color and came to rest 

 there, while gobies avoided red, refusing to go through a red 

 passageway until it had been sanded. Red, yellow, green, and 

 blue were chosen in order by Gasterosteus. This author thinks 

 that her results show a color sense, but the possibility that the 

 fishes were reacting to brightness does not seem to be eliminated. 



Feeding experiments. In such experiments a motive is intro- 

 duced. Discrhnination on the part of the fish is indicated by 

 an attempt to take food. 



Zolotnitzky ('01) placed pieces of wool of different colors 

 having the shape and size of chironomid larvae on the wall of 

 an aquarium containing Macropodes. The fish snapped often 

 at the red wool, less frequently at the yellow, and left the other 

 colors untouched. 



Frisch ('14) placed bits of food on colored paper of various 

 shades. Fishes that had been accustomed to eat j^ellow food 

 snapped at it in preference to other colors and red food was 

 taken by fishes trained to eat red. Red food was taken on a 

 black background, but black food was not taken from a black 

 surface nor gray from a gray background. Red and yellow 

 were often confused with each other and with purplish red, but 

 not with gray, green, or blue. 



Minkiewicz ('12) taught a Julis \ailgaris to seek food dropped 

 into the tank thi'ough a blue tube and at the same tune to dis- 

 regard a piece of thread dropped in through a yellow tube. 



Goldsmith ('12) reports that plaice and gobies learned to take 

 food from colored forceps thrust into the water, and later chose 

 the color which had been associated with food even when the 

 relative position of the forceps was changed. The fishes per- 

 sisted in examining the same forceps after an interval of four 

 days even when no food was present. 



Washburn and Bently ('06) were able to estabUsh an associ- 

 ation involving 'color' discrimination in the creek club. This 

 fish w^as fed from forceps to which red sticks were attached. 

 When a similar pair of forceps attached to green sticks was offered 

 simultaneously, the fish preferred the red forceps, even when 



