96 A GUIDE FOR THE STUDY OF ANIMALS 



Summary. 



1. Name four uses of color. 



2. Name four ways an animal is protected by being like 

 its background. 



3. Name one way it is protected by being unlike its 

 background. 



4. What disadvantages in this method of protection } 



C. Animal Associations 



To show Another Method of Protection from Enemies 

 Materials. 



Specimens, charts, etc, illustrating animal associations. 



Definitions. 



Animal communities, associations of many animals of 

 the same species in communities in which there is a greater 

 , or less division of labor. 



Gregarious, associations where there is but little division 

 of labor. 



Parasitism, an association where one animal lives at the 

 expense of the other. The animal on which the parasite 

 lives is called the host. If there are two hosts during the 

 life cycle of the parasite, the second host is called an inter- 

 mediate host. 



Symbiosis, an association where two animals live to- 

 gether in mutually helpful relations. 



Commensalism, an association where two animals live 

 together in relations not mutually helpful but without in- 

 jury to either. 



Observations and questions. 



Note. — To find answers to many of these questions it will be necessary 

 to refer to the reference books in the laboratory. 



