132 



SUMATRA. 



[chap. VHl 



Tbe end of the upper wings terminates in a fine 

 point, just as the leaves of many tropical shrubs 

 and trees are pointed, isrhile the lower win^ are some- 

 what more obtuse, and are lengthened out into a short 

 thick tan. Between these two points there runs a dark 

 curved line exactly representing the midrib of a leaf, and 

 from this radiate on each side a few oblique marks which 

 well imitate the lateral veins. These marks are more 

 clearly seen on the outer portion of the base of the wings, 

 and on the inner side towards the middle and apex, and 

 they are pi*oduced by strije and markings which are ver}^ 

 common in allied species, but which are here modified and 

 stienothened so as to imitate more exactly the venation of 

 a leaf. The tint of the under surface varit-s much, but 

 it is always some ashy brown or reddish colour, which 

 matches with those of dead leaves. The habit of the 

 species is always to rest on a twig and among dead or 

 dry leaves, and in this position with the \vings closely 

 pressed together, then- outline is exactly that of a modi^- 

 rately-sized leaf, slightly curved or shrivelled. Tlie tad 

 of the hind wings forms a perfect stalk, and touches the 

 stick while the insect is supported by the middle pair of 

 legs, which are not noticed among the twigs and fibres 

 that surround it. The head and antenn® are di'awn back 

 between the wings so as to be quite concealed, and there 

 is a little notch hollowed out at the very base of the 

 wings, which allows the head to be retmcted sufficiently. 

 All tliese varied details combine to produce a disguise 

 that is so complete and marvellous as to astonish every 

 one who observes it; and the habits of the insects are 

 such as to utiliza all these peculiarities, and render them 

 available in such a manner as to remove all doubt of 

 the pui-pose of tliis singular case of mimicr}% which ia 

 undoubtedly a protection to the insect. Its strong and 

 swift flight Ls sufficient to save it from its enemies when 

 on the wing, bnt if it were equally conspicuous when at 

 rest it could not long escape extinction, owing to the 

 attacks of the insectivorous birds and reptiles that abound 

 in the tropical forests. A very closely allied species, 

 KalUma ijiachis, inhabits India, where it is veiy common, 

 and specimens are sent in everj^ collection from the 



