INDIVIDUAL DIFFERENTIATION AND ADAPTATION. 



destruction of their enemies than if these should lose their 

 power of capturing their prey. 



159. Adaptations for Protection. In addition to the 

 alternatives of fighting or fleeing, the animals which are preyed 

 upon have very interesting and effective qualities that make 

 for safety. Many forms, as the Crustacea, have permanent 



FIG. 57. 



FIG. 57. Nestling Mourning Doves (Zenaidura macrourd). From U. S. Dept. Agri- 

 culture Year-Bopk, 1900. 



Question on the figure. Is there anything suggestive of protective 

 markings? What are the nesting habits of the dove? What character of 

 nest is constructed? 



outer coverings; most mollusks have a box arrangement into 

 which they can retire when threatened by attack; others by 

 burrowing or otherwise come to occupy obscure corners in 

 nature where enemies find it difficult to follow. Forms as 

 widely different as the mole and the chamois find safety in 

 retirement. This hiding-theme may be wrought out in ways 

 almost equally effective by what is called protective resem- 

 blance. By this is meant that the animal becomes less easily 



