76 DOMESTICATED ANIMALS ANID PLANTS 
again to Fig. 10. Like most colored insects this butterfly pre- 
fers localities colored like himself, and he often lights and sits 
for a considerable time on trees and poles more or less covered 
with lichens, from which he is indistinguishable except on the 
closest scrutiny. 
This is true mimicry. The remarkable part of this particular 
case is the habit of lighting and the manner of sitting. The 
butterflies as a rule fold the wings together on the back im- 
mediately upon lighting, but this particular species, instead of 
folding the wings, spreads them flat and sits with them in that 
position. The resemblance to the lichen is not very exact, but 
Fic. 11. Lower and upper surface respectively of Aa phidile (author’s 
specimen), a tropical butterfly of the color of a dead leaf 
it is close in a general way, and the writer has often studied 
for some minutes to find the specimen and make out the 
outlines even when he had seen the creature in the very act 
of lighting. 
Mimicry in structure is illustrated by another butterfly, which, 
with its wings folded together, exhibits a venation quite like 
that of a small leaf of the beech or similar tree. Being of a 
brown color, its resemblance to a dead leaf is close. It has two 
very different methods of lighting. Commonly it folds its wings 
not after lighting but before, in which case it flutters to the 
ground not unlike a dead leaf falling from the tree. In other 
cases it lights directly upon twigs or stems, in which instance it 
