540 



THE WONDER OF LIFE 



KalUma, which is conspicuously coloured on the upper 

 surface, but becomes like a withered leaf when it folds 

 its wings together and exposes the brown under surface 

 (Fig. 11). As we have noted, the nervures on the wings look 



like the veins on a 

 leaf, and the sug- 

 gestion of a mid- 

 rib increases the 

 resemblance. 

 Spots on the 

 wings look like 

 holes on the leaf, 

 and so on. In 

 fact, perfection is 

 attained by the 

 combination of a 

 number of items. 

 Even the fact 

 that the colora- 

 tion of the under 

 surface and the 

 position of spots 

 may vary a Uttle 



FlQ. 85. — Two spiders : I. Cserostris mitralis " " 



like a knot on a, twig ; and II, Qmitho- vantageous,since 

 soatoides decipiens, like a bird's dropping. ,-, r xx _fl i, 

 {After Vinson and Piekard-Cambridge.) the butterfly Jias 



thus a general 

 resemblance to different kinds and states of withered leaves. 

 Protective coloxir-resemblance is seen at its best in cases 

 where the animal can adjust itself to the coloration of the 

 surface on which it is resting ; and there is no better illus- 

 tration than that of plaice and other flat-fishes, which are 



