VIII 
ORIGIN AND USES OF COLOUR IN ANIMALS 
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 protective, among them being three 
species of butterflies whose undersides are silvery, and which 
are thus effectually protected when at rest. 1 A common 
African butterfly (Aterica meleagris) always settles on the 
ground with closed wings, 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 Carne- 
roons were light brown with numerous small white spots, the 
soil of those countries being light brown clay with small 
quartz 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. 2 
Many butterflies, in all parts of the world, resemble dead 
leaves on their under side, but those in which this form 
of protection 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 where 
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 twig, 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 antennae fit exactly between the 
closed upper wings so as not to interfere with the outline, 
1 Trans. Ent. Soc. Lond., 1878, p. 185. 
2 Ibid. ( Proceedings, p. xlii.) 
