III PROTECTIVE RESEMBLANCES AMONG ANIMALS 43 
the same time drawing in their legs and antennz, which fit so 
perfectly into cavities for their reception that the insect 
becomes a mere oval brownish lump, which it is hopeless to 
look for among the similarly coloured little stones and earth 
pellets among which it lies motionless. 
The distribution of colour in butterflies and moths re- 
spectively is very instructive from this point of view. The 
former have all their brilliant colouring on the upper surface 
of all four wings, while the under surface is almost always 
soberly coloured, and often very dark and obscure. The 
moths on the contrary have generally their chief colour on 
the hind wings only, the upper wings being of dull, sombre, 
and often imitative tints, and these generally conceal the 
hind wings when the insects are in repose. This arrange- 
ment of the colours is therefore eminently protective, because 
the butterfly always rests with his wings raised so as to con- 
ceal the dangerous brilliancy of his upper surface. It is 
probable that if we watched their habits sufficiently we should 
find the under surface of the wings of butterflies very fre- 
quently imitative and protective. Mr. T. W. Wood has 
pointed out that the little orange-tip butterfly often rests in 
the evening on the green and white flower heads of an 
umbelliferous plant, the wild chervil,! and that when observed 
in this position the beautiful green and white mottling of the 
under surface completely assimilates with the flower heads 
and renders the creature very difficult to be seen. It is 
probable that the rich dark colouring of the under side of our 
peacock, tortoiseshell, and red-admiral butterflies answers a 
similar purpose. 
Two curious South American butterflies that always settle 
on the trunks of trees (Gynecia dirce and Callizona acesta) 
have the under surface curiously striped and mottled, and 
when viewed obliquely must closely assimilate with the appear- 
ance of the furrowed bark of many kinds of trees. But the most 
wonderful and undoubted case of protective resemblance in a 
butterfly which I have ever seen, is that of the common Indian 
Kallima inachis, and its Malayan ally, Kallima paralekta. 
The upper surface of these insects is very striking and showy, 
as they are of a large size, and are adorned with a broad band 
1 Anthriscus sylvestris. 
