PLATE 1 



EXPLANATION OF FIGURES 



The photographs in this plate, which show the influence of temperature on 

 the distribution of the retinal pigment of fishes, are all at a magnification of 170 

 diameters. 



1. Ameiurus, 5°C. in the light. 



2. Ameiurus, 25°C. in the light. 



3. Ameiurus, 5°C. in the dark. 



4. Ameiurus, 25°C. in the dark. 



5. Fundulus, 5°C. in the light. 



6. Fundulus, 25°C. in the light. 



7. Fundulus, 5°C. in the dark. 



8. Fundulus, 25°C. in the dark. 



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