130 A BOOK OF INSECTS 



but the deception is heightened by the shape of the wings 

 and the manner in which they are held when the insect is 

 at rest. The tip of the fore-wing is pointed, and the hind- 

 wing has a short tail like a leaf-stalk ; while, when the 

 butterfly settles, the wings are brought together over the 

 back, the head and antennae being concealed between 

 them. Moreover, just as dead leaves vary in colour, so 

 a corresponding variety of tinting is seen on the butter- 

 flies' wings. Again, small holes are often bitten in leaves 

 by caterpillars ; and this possibility is anticipated, so to 

 say, in the butterfly by a spot, clear of scales, which exists 

 in each fore-wing. When the insect is at rest these spots 

 are brought exactly opposite one another, with the result 

 that the transparent membranes produce the effect of a 

 small, irregular puncture. 



Many other butterflies and moths simulate dead leaves 

 in various stages of decay ; while some — such as our own 

 green hair-streak butterfly (Tliecla rubi) — resemble living 

 foliage. But the most wonderful " green leaf insects " 

 belong to the genus Phyllium, of the family Phasmidas. 

 They are found only in the tropics of the Old World, and 

 have a peculiar penchant for island life. The females are 

 much more leaf-like than the males because the tegmina, 

 or fore- wings (usually reduced or absent in other members 

 of the family), are large and foliaceous. In both sexes, 

 however, the body is greatly flattened, while its colour is a 

 vivid green which, when submitted to spectral analysis, is 

 said not to differ from that of the living leaf. It is even 

 recorded that " Mr. J. J. Lister, when in the Seychelles, 

 brought away living specimens of Phyllium ; and these, 

 becoming short of food, nibbled pieces out of one another, 

 just as they might have done out of leaves, . . . but con- 

 fined their depredations to the leaf-like appendages and 

 expansions." Still more remarkable is the fact that the 



