VIII ORIGIN AND USES OF COLOUR IX AXDIALS 207 



of white and silvery foliage or bark, sometimes of dazzling 

 brilliancy, and that many insects and their larvae have brilliant 

 silvery tints which are j^rotective, among them being three 

 species of butterflies whose undersides are silvery, and which 

 are thus effectually protected when at rest.^ A common 

 African butterfly (Aterica meleagris) always settles on the 

 ground with closed wdngs, which so closely resemble the soil 

 of the district that it can with difficulty be seen, and the 

 colour varies with the soil in different localities. Thus 

 specimens from Senegambia were dull brown, the soil being 

 reddish sand and iron- clay; those from Calabar and Came- 

 roons were light brown with numerous small white spots, the 

 soil of those countries being light brown clay with small 

 Cjuartz pebbles ; while in other localities where the colours of 

 the soil were more varied the colours of the butterfly varied 

 also. Here we have variation in a single species which has 

 become specialised in certain areas to harmonise with the 

 colour of the soil.^ 



Many butterflies, in all j)arts of the world, resemble dead 

 leaves on their under side, but those in which this form 

 of j^rotection is carried to the greatest perfection are the 

 species of the Eastern genus Kallima. In India K. inachis, 

 and in the larger Malay islands K. paralekta, are very com- 

 mon. They are rather large and showy butterflies, orange 

 and bluish on the upper side, with a very rapid flight, and 

 frequenting dry forests. Their habit is to settle always ^^-here 

 there is some dead or decaying foliage, and the shape and 

 colour of the wings (on the under surface), together with the 

 attitude of the insect, is such as to produce an absolutely 

 perfect imitation of a dead leaf. This is effected by the 

 butterfly always settling on a Uvig, with the short tail of the 

 hind wings just touching it and forming the leaf- stalk. 

 From this a dark curved line runs across to the elongated tip 

 of the upper wings, imitating the midrib, on both sides of 

 which are oblique lines, formed partly by the nervures and 

 partly by markings, which give the effect of the usual veining 

 of a leaf. The head and antennse fit exactly between the 

 closed upper wings so as not to interfere T\dth the outline, 



1 Trans. Eat Soc. Lond., 1878, p. 185, 

 ^ Ibid. {Proceedings, p. xlii.) 



