EXERCISE 131 



Problem. What is the influence of light and color on pigmentation ? 



What to use. A living fence lizard, chameleon, toad, snake, or fish. Papers of various colors 

 and shades. 



What to do. By means of the papers change the background of the animal in various ways, giving 

 several minutes for each possible reaction. Note any changes that take place in the appearance of the animal. 



Questions. 1. Does the animal respond more readily to achange of shade (illumination) or to a 

 change of color ? 



2. Does it respond more readily to an increase or to a decrease in illumination ? 



3. Can different parts of the body respond in opposite ways ? 



4. Do the changes depend upon the animal's seeing the colors ? 



5. How does temperature affect the color of the skin ? 



6. How does temperature affect the response of the animal to changes in the background ? 



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