328 THE WOELD OF LIFE 



enemies, there is ample evidence. Almost all students of the 

 subject admit that the markings and tints of insects often 

 resemble their environment in a remarkable manner, and that 

 this resemblance is protective. The eye-like markings, either 

 on the upper or under surfaces, are often seen to be imitations 

 of the eyes of vertebrates, when the insect is at rest, and this 

 also is protective. The brilliant metallic or phosphorescent 

 colours on the wings of butterflies may serve to distract ene- 

 mies from attacking a vital part, or, in the smaller species 

 may alarm the enemy by its sudden flash with change of posi- 

 tion. But while the colours are undoubtedly useful, the mode 

 of producing them seems unnecessarily elaborate, and adds a 

 fresh complication in the way of any mechanical or chemical 

 conception of their production. 



