204 ANIMAL LIFE 



gulls and terns, colored like the sea. In the brooks most 

 fishes are dark olive or greenish above and white below. 

 To the birds and other enemies which look down on them 

 from above they are colored like the bottom. To their fish 

 enemies which look up from below, their color is like the 

 white light above them, and their forms are not clearly 

 seen. The fishes of the deep sea in perpetual darkness are 



FIG. 126. Alligator lizard (Gerrhonottts sdndcauda) on granite rock. Photograph 

 by J. O. SNYDEB, Stanford University, California. 



inky violet in color below as well as above. Those that 

 live among sea-weeds are red, grass-green, or olive, like 

 the plants they frequent. General protective resemblance 

 is very widespread among animals, and is not easily appre- 

 ciated when the animal is seen in museums or zoological 

 gardens that is, away from its natural or normal environ- 

 ment. A modification of general color resemblance found 

 in many animals may be called variable protective resem- 

 blance. Certain hares and other animals that live in 

 northern latitudes are wholly white during the winter when 

 the snow covers everything, but in summer, when much of 

 the snow melts, revealing the brown and gray rocks and 



