62 MIMICRY, AND OTHER PROTECTIVE 
said to be absolutely perfect; and the protection which 
it affords is sufficiently indicated by the abundance of 
the individuals that possess it. 
The Rev. Joseph Greene has called attention to the 
striking harmony between the colours of those British 
moths which are on the wing in autumn and winter, 
and the prevailing 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 corres- 
ponding colours. Orgyia antiqua, O. gonostigma, the 
genera Xanthia, Gla, 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 al- 
ready 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 
distinguished from the grey 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 re- 
semble the dung of birds dropped on leaves, and on this 
point Mr. A. Sidgwick, in a paper read before the 
Rugby School Natural History Society, gives the 
