vi DEFENCES OF INSECTS 215 



shape, the insect passes muster as a bit of dead and 

 curled up leaf, or as the excreta of birds or snails. 

 Imitation of the excrement of birds is however rare 

 and exceptional. 



In mature Lepidoptera, the most wonderful and 

 undoubted case of the higher form of protective 

 resemblance is that of the Malayan Leaf-butterfly, 

 Kallima paralekta, and its Indian ally K. inackis. The 

 method of concealment has been described by Dr. 

 Wallace, who was the first to observe it, in his Malay 

 Archipelago, and elsewhere. The upper surfaces of 

 the wings are showy, conspicuous, and large, with a 

 broad rich orange band across the fore-wings on a 

 deep bluish ground. Opposed to this brilliancy the 

 under surfaces, though varying greatly, in every case 

 are of sombre tint, of some shade of gray, or brown, or 

 ochre, such as is common among dead or withered 

 leaves. 'Mid leaves of the kind on a nearly upright 

 twig the butterfly rests, and in this position with the 

 wings tightly closed over the back, thus exhibiting 

 their under surfaces, is in exact agreement with its 

 surroundings, the irregular outline of the folded wings 

 forming a direct and finished representation of a 

 moderate sized leaf, shrivelled or withered in some 

 stage of decay. The tip of the fore-wing is produced 

 into a point, a common form of leaves in the tropics ; 

 the hind-wings terminate in a short narrow tail, which 

 touches the branch, and typifies a perfect leaf-stalk. 

 From end to end along the whole length of the 

 supposed leaf runs a distinct dark line, the seeming 

 mid-rib ; from this on either side radiate oblique lines 

 imitative of a leaf's lateral venation.* The butterfly 



