II PROTECTIVE RESEMBLANCES AMONG ANIMALS 45 
they were generally searched for in vain, for while gazing 
intently at the very spot where one had disappeared, it would 
often suddenly dart out, and again vanish twenty or fifty 
yards farther on. On one or two occasions the insect was 
detected reposing, and it could then be seen how completely 
it assimilates itself to the surrounding leaves. It sits on a 
nearly upright twig, the wings fitting closely back to back, 
concealing the antennz and head, which are drawn up between 
their bases. The little tails of the hind wing touch the 
branch, and form a perfect stalk to the leaf, which is sup- 
ported in its place by the claws of the middle pair of feet, 
which are slender and inconspicuous. The irregular outline of 
the wings gives exactly the perspective effect of a shrivelled 
leaf. We thus have size, colour, form, markings, and habits 
all combining together to produce a disguise which may be 
said to be absolutely perfect; and the protection which it 
affords is sufficiently indicated by the abundance of the in- 
dividuals that possess it. 
The Rev. Joseph Greene has called attention to the strik- 
ing harmony between the colours of those British moths 
which are on the wing in autumn and winter, and the prevail- 
ing tints of nature at those seasons. In autumn various 
shades of yellow and brown prevail, and he shows that out of 
fifty-two species that fly at this season, no less than forty-two 
are of corresponding colours. Orgyia antiqua, O. gonostigma, 
the genera Xanthia, Glea, and Ennomos are examples. In 
winter, gray and silvery tints prevail, and the genus Chematobia 
and several species of Hybernia which fly during this season 
are of corresponding hues. No doubt if the habits of moths 
in a state of nature were more closely observed, we should 
find many cases of special protective resemblance. A few 
such have already been noticed. Agriopis aprilina, Acronycta 
psi, and many other moths which rest during the day on the 
north side of the trunks of trees, can with difficulty be dis- 
tinguished from the gray and green lichens that cover them. 
The lappet moth (Gastropacha querci) closely resembles both 
in shape and colour a brown dry leaf; and the well-known 
buff-tip moth, when at rest, is like the broken end of a lichen- 
covered branch. There are some of the small moths which 
exactly resemble the dung of birds dropped on leaves, and on 
