PROTECTIVE RESEMBLANCE 129 



Oft-cited examples are the moths which rest upon tree 

 trunks during the daytime. Many of them have brightly 

 coloured hind-wings; and if they contravene their nocturnal 

 instinct and sally forth into the sunlight, they become at 

 once objects calculated to attract hungry birds. Rut when 

 seated upon a tree trunk in their customary attitude of 

 repose, they are effectually concealed by the colours of 

 their fore-wings, which harmonise with the rough surface 

 of the bark. Other moths, such as the marvel-du-jour 

 (Agriopis aprilina), have the fore-wings coloured so as to 

 resemble lichen. Moreover, this particular type of colour- 

 ing may be seen in many insects of other orders, among 

 them being a wonderful beetle from Madagascar, known 

 as Lit hi nus nigrocristatus, which can only be distin- 

 guished from a tuft of lichen after the closest scrutiny. 

 In all such cases we notice that the sharp outline of the 

 insect is obliterated by a cunning arrangement of dark 

 and light tints ; and this is of first importance, for no 

 matter how closely the colouring of an insect may accord 

 with its background, a tell-tale outline would detract from 

 the concealing value of its colouring. 



Turning from general to special protective resemblance, 

 we find a bewildering array of examples. Perhaps the 

 most convincing are the butterflies of the genus Kallima — 

 the "leaf butterflies" par excellence — which are found in 

 India and the Malay Archipelago. When flying in the 

 full sunlight, with their wings flashing purple and orange, 

 they are very conspicuous. But when they pitch upon 

 the ground, or upon a twig, they are immediately trans- 

 formed into brown and withered leaves. Experienced 

 naturalists have been at a loss to discover the exact where- 

 abouts of a Kallima butterfly, although they have actually 

 watched it settle. This marvellous capacity for hiding is 

 due chiefly to the leaf-like colouring of the wings beneath ; 



