414 



EVOLUTION AND ANIMAL LIFE 



in leaves by insects, but in the butterfly imitated by two small 

 circular spots free from scales and hence clear and transparent. 

 With the head and feelers concealed beneath the wings, it makes 

 the resemblance wonderfully exact. 



Fig. 257. — Kallima, the "dead-leaf butterfly.'* 



The moths of the genus Cymatophora, and their larva? also, 

 mostly harmonize excellently with the gray bark on which they 

 rest, the moths adding to their general simulation the curioii: 

 habit of resting, often with folded Vvings, at an angle of foruy^ 

 five degrees with the tree trunk, head downward, with the 

 curiously blunt and uneven wing tips projecting, so as to imitate 



