KNOWLEDGE & SCIENTIFIC NEWS. 



[April, 1904. 



The same may be said of countless other moths, especi- 

 ally of the great Noctiia group ; and it is interesting to 

 trace how closely the colour of the fore wings in a given 

 species corresponds to its habitual resting place. The 

 appearance of all kinds of bark, of moss}' twigs and of 

 lichen-covered rocks is faithfully reproduced ; nor is it 

 necessary to search beyond the moths of our own islands 

 for striking examples. 



Many butterflies, especially of the great group .Vvw;/'/ia- 

 liiuv, possess — in the tints of their under side— a general 

 resemblance to the ground upon which they habitually 



Hamanumida dedalus. Africa. 



settle. Moreover, many species seem to have acquired 

 the trick of inclining their folded wings out of the 

 perpendicular, by this means covering, or minimising, 

 their own shadow, as well as bringing the protectively 

 coloured underside into more prominent view. This 

 habit may be observed in many of our common " brown " 

 butterflies — for instance, in Pyrarga mcgaera and in Satyvus 

 semde. In connection with this apparently acquired aid 

 to protected resemblance, the habits of Hamanumida 

 dcdalus, an African butterfly, are exceedingly interesting. 

 It is authoritatively stated that this insect rests in West 

 Africa with its wings folded over its back after the 



soil, is exposed to view. In South Africa, on the other 

 hand, the same insect sits with its wingsexpanded, show- 

 ing the brownish grey upper side which harmonises with 

 the colours of the rocks in that region. 



Many of the Coleoptcra, from their colour, are almost 

 indistinguishable when resting upon lichen-incrusted bark. 

 The accompanying photograph of a Longuorn from 

 Bhutan admirably illustrates this phase of general protec- 

 tive resemblance. Although the insects are in full view, 

 the casual glance quite fails to detect their presence. 

 This surprising result is largely gained by the manner in 

 which the colour is, as it were, cut up into dark and light 

 patches. This is particularly noticeable in the long 

 antenna", the sharp outline of which is entirely effaced 

 from their being coloured in alternate lengths of black 

 and grey. 



Turning from general to special protective resemblance, 

 we find a number of extremely interesting and remark- 

 able examples, especially among exotic insects. The 

 butterflies of the genus Kallima — " leaf butterflies," as 

 they are popularly called — bear striking testimony to the 



Hamanumida dedalus. (Underside.) .Mrica. 



common habit of butterflies, in which position its tawny 

 under surface, which agrees with the general tone of the 



Apallmna ducalis. Male and Female. Bhutan. On Lichenous Bark. 



powers of natural selection. When flying in the full 

 sunlight, their wings flash with colour, but directly they 

 come to rest upon a twig they are, to all appearances, 

 brown and withered leaves. This sudden transformation 

 is made possible by the tinting of the under surface of 

 the wings, and by the curiously erect attitude which the 

 insect is able to assume — its wings drawn upright over 

 the back and its head and antennae concealed between 

 their anterior margins. When we consider the mar- 

 vellous accuracy of the colour imitation, the uncommon 

 shape of the insect's wings and its unusual pose, the leaf 

 butterfly must still be ranked as one of the most amazing 

 instances of protective resemblance yet recorded, not- 

 withstanding the many marvels which have been brought 

 to our notice within recent years. 



The larvae of moths grouped under the title Geome- 

 tridcT usually bear a curiously accurate resemblance to 

 liitle twigs or sticks, both in shape and in their brown 



