COLOR IN ANIMALS 121 



brightly colored like the blossoms, their color rendering 

 them inconspicuous (Plate 75, A). Spiders are exposed to 

 the attacks of enemies, especially of certain wasps which 

 capture them, paralyze them by stinging them, and then 

 use them to provision their nests, the young wasps feeding 

 upon the living spiders. They therefore need protection. 



Of special interest are the protective seasonal changes 

 of color, seen in some northern animals; for example, sev- 

 eral species of ptarmigan and the New England and Cana- 

 dian hare, which are white in winter, resembling the snow, 

 are grayish or brownish in summer like the dead leaves and 

 the rocks among which they are found, while in the spring 

 and fall, while shedding their feathers or hair, they are a 

 spotted gray and white or brown and white, bringing them 

 into color harmony with their environment, in which patches 

 of snow are scattered among the rocks or leaves (Plate 57). 



Some animals are able rapidly to change their color, 

 thus keeping them in harmony with the varying color of 

 their surroundings as they move from place to place. The 

 chameleon, the little Anolis of our southern states, some 

 frogs, and many kinds of fishes, especially tropical fishes, 

 have this ability (Plate 58). 



It is well known that the pupae of most butterflies 

 are colored to correspond to their environment. Professor 

 Poulton, experimenting upon certain species of butterflies, 

 has shown that by placing the full-grown caterpillars in 

 boxes lined with different colored paper, pupae of colors 

 corresponding to that of the paper with which they were 

 surrounded can be obtained (Plate 59). 



There are many instances of special resemblance, in 

 color or in form or in both, between a species of animal 



