494 GERTRUDE MAREAN WHITE 



swim in schools show no evidence of an intelHgent purpose in 

 swinuning in any particular direction other than that one indi- 

 vidual, not always the same one, happens to make a sudden dart. 

 The movement is perceived by the rest and immediately followed. 

 If one of the fishes chances to obtain a bit of food, the others 

 attracted by the motion, are as likely to pounce upon the fortu- 

 nate one as they are to attack the food lying close at hand. They 

 strike their rival quite as often on the tail or fins as on the mouth. 

 If the aggregation of fishes into schools represents the beginning 

 of social consciousness it must be very dim and obscure. It is 

 quite possible that fishes of the same school are attracted to 

 each other by characteristic odors and the movements peculiar 

 to the species. There seems to be no clear proof of the subor- 

 dination of the welfare of the individual to the general good of 

 its kind, nor any decided development of a social or gregarious 

 instinct. 



GENERAL SUMMARY 



1. Mudminnows were able to discriminate between the fol- 

 lowing wave-lengths of light: red 600^ to 730^ and green 510^ 

 to 570m, red 600^ to 730/i, and blue 420m to 480m, yellow 580m 

 to 630m, 660m to 710m, and green 510m to 570m, as is shown by 

 associations of paper and food with these colored lights (pp. 

 462-474). 



2. Varying the intensity of the red and green lights and the 

 yellow and green lights from 1.4 cm. to 4.9 cm. did not affect 

 such discrimination, indicating that the reactions were to color 

 rather than to intensity. This conclusion is further supported 

 by the fact that fishes which had previously shown that they 

 perceived differences between monochromatic gelatin filters were 

 not able to distinguish between photographic plates which had 

 been 'fogged' to different shades of gray (pp. 466-474). 



3. Sticklebacks were not able to discriminate between the 

 following wave-lengths of light: blue 420m to 480m and yellow 

 580m to 630m, 660m to 710m, but were able to discriminate -be- 

 tween red 600m to 730m and green 510m to 570m, forming asso- 

 ciations of food and paper with them. These associations per- 



