ADAPTATION FOR THE INDIVIDUAL 121 



ways have an unpleasant taste, but when they do it 

 certainly is most unpleasant. 



There remains to be considered the most effective 

 plan yet mentioned of escaping the enemy, and that 

 is of really escaping. In all the devices we have con- 

 sidered thus far the enemy is eluded. When the 

 creature lies quiet, or finds safety in its protective 

 coloration, or in its bad taste, or unpleasant odor, it 

 still remains in the presence of the enemy. A more 

 progressive plan altogether is to escape the enemy 

 by flight. The great advantage of this plan lies in 

 the fact that the acquisition is valuable for every pur- 

 pose. The creature then can escape the enemy, can 

 range widely for food or for a mate. This gives it an 

 enormous advantage in the struggle for life. The 

 power to fly, in insects, was doubtless originally 

 gained in the attempt to escape the enemy. Among 

 many of the lower animals it is nearly the only pur- 

 pose that flying serves. Later on it enables the ani- 

 mal to pass from one food locality to another. In a 

 few creatures it plays an effective part during the 

 mating season. These last are probably both derived 

 powers, and the original function was that of escape 

 from the enemy. The grasshopper has grown its long 

 legs to serve him for safety, and through them it is 

 helped along, moving about chiefly by leaps when it 

 wishes to go any material distance. It is only toward 



