476 GERTRUDE MAREAN WHITE 



Fig. 7 Curves representing the results of experiments on the discrimination 

 of colors and light intensities by sticklebacks. Construction of curves same as 

 in preceding figures. 



A. Stickleback no. 65. Blue and yellow lights, blue indicated presence of 

 food and yellow indicated paper. Duration of experiment, 18. days, April 28 to 

 May 15. 



B. Stickleback no. 66. Blue and yellow lights, blue indicated presence of 

 food and yellow indicated paper. Duration of the experiment, 16 days, April 

 26 to May 13. 



C. Stickleback no. 65. Green and red lights; green indicated presence of 

 food and red indicated paper. Duration of the experiment, 21 days, May 16 

 to June 5. 



D. Stickleback no. 66. Green and red lights, green indicated presence of 

 food and red indicated paper. Duration of the experiment, 17 days, May 16 to 

 June 1. 



E. Stickleback no. 65. Light shining through photographic plates 'fogged' 

 different shades of gray, the darker plate (exposed to light 4 seconds) indicated 

 presence of food and the lighter plate (exposed to light 1 second) indicated paper. 

 Duration of the experiment, 32 days, March 27 to April 27. 



F. Stickleback no. 66. Light shining through photographic plates 'fogged' 

 different shades of gray, the darker plate (exposed to light 4 seconds) indicated 

 presence of food and the lighter plate (exposed to light 1 second) indicated paper. 

 Duration of the experiment, 32 days, March 27 to April 27. 



Fig. 8 Curves representing the results of experiments on the discrimination 

 of colored lights by sticklebacks. Construction of curves and lettering same as 

 in figure 1. 



A. Stickleback no. 46. Gi'een and red lights. During the first 34 days (b-c) 

 green indicated presence of food and red indicated paper; during the remaining 

 56 days, red indicated presence of food and green indicated paper. The duration 

 of the entire experiment was 90 days, December 5 to April 3. 



B. Stickleback no. 50. Green and red lights. During the first 32 days (b-c) 

 green indicated presence of food and red indicated paper; during the remaining 

 92 days (c-d) red indicated food and green indicated paper. During the last 

 20 days the lights were varied in intensity (v-v). Duration of the entire ex- 

 periment, 124 days, January 6 to May 8. 



Fig. 9 Curve representing the results of experiment on the discrimination 

 of patterns by mudminnow no. 27. Construction of curves same as in preceding 

 figures. A square of black paper 2.7 cm. indicated presence of food and four 

 black dots 1 cm. in diameter indicated paper.' Duration of the experiment, 38 

 days, February 27 to April 5. 



Fig. 10 Curves representing the results of experiments on the discrimina- 

 tion of calves' liver and gray paper offered alternately to stickleback no. 57. 

 As in figure 1, only the errors of each day's record are shown in the curves. 



A. Duration of the experiment, 35 days, October 24 to November 28. 



B. Repetition of experiment represented by curve A. This was begun 44 

 days after the first experiment had been discontinued. Duration of the experi- 

 ment, 30 days, January 12 to February 10. 



