ADAPTIVE COLORATION 217 
the illuminated and the shaded side of a mid-rib, and the side- 
veins as well are imitated; there are even small scattered black 
spots resembling those made on the leaf by a species of 
fungus. Furthermore, the butterfly habitually rests, not 
among green leaves, where it would be conspicuous, but among 
leaves with which it har- 
; s ; Fic. 240. 
monizes in coloration. 
Notwithstanding a recent 
discussion as to whether 
it usually rests in pre- 
cisely the same position 
as a leaf, this insect cer- 
tainly deceives  experi- 
enced entomologists and 
presumably eludes birds 
and other enemies by 
means of its deceptive 
coloration. 
Some of the tropical 
Phasmidz _ counterfeit 
sticks, green leaves, or 
dead. leaves with minute 
accuracy. Our common 
phasmids, Diapheromera 
femorata and veliei (Fig. 
240), are well known as 
me suicke insects; ; itideed, 
it is not necessary to go 
beyond the temperate zone 
Diapheromera veliei, on a twig. Natural size. 
to find plenty of examples 
of protective resemblance. Geometrid caterpillars imitate twigs, 
holding the body stiffly from a branch and frequently reprodu- 
cing the form and coloration of a twig with striking exactitude ; 
and the moths of the same family are often colored like the 
bark against which they spread their wings. Even more per- 
fectly do the Catocala moths resemble the bark upon which 
