252 



A YEAR IN SCIENCE 



Change due to new conditions. New conditions may 

 so alter a species of animal that it no longer exactly 

 resembles the form from Avhich it came. For example, 

 animals sometimes adapt themselves to caves. As a 

 result they become blind and lose their color. 



Adaptation. There are so many animals, and conse- 

 quently so much strife for a place in this crowd, that 

 all animals must adjust themselves to conditions in 

 order to survive. If they can not change so as to be 

 fitted for given conditions, they die. We have already 



of Field Museum of Natural History. 

 Fig. 108. The polar bear is adapted for life in the Arctic regions. 



noted the inability of a polar bear to live in a warm 

 climate. 



All animals are more or less fitted, or adapted, to 

 their environment and to the kind of life which they 



