PROTECTIVE RESEMBLANCES IN INSECTS. 27 



and reluctantly even when we literally kicked it up. A cir- 

 cumstance most worthy of note is that the colouring of this 

 curious grasshopper copies that of the particular little group of 

 stones among which it lives ; and I found this to be the case in 

 quite a limited extent of ground, a set of mottled stones occupying 

 a small space having among them Batrachotetrix of corresponding 

 tints, while but a little way off a set of uniformly dark or light 

 stones harboured grasshoppers of like hues. 



Several South-African butterflies are protected at rest by the 

 similarity of the under-surface of their wings to the ground on 

 which they settle. The beautiful Jiinonla cehrene and J. clelia 

 are thus often rendered almost invisible ; and as the former 

 species has been observed by Colonel Bowker to be much hunted 

 by lizards, no doubt the resemblance is of considerable service to 

 them. The same kind of protective colouring is shown by many 

 of the small butterflies belonging to the genus Zeritis — a very 

 characteristic Cape group. 



The bark of trees and the lichens which cling to it find in- 

 numerable faithful cojjyists among insects, whole groups of 

 beetles and moths more or less exactly reproducing each rugosity 

 and tint of their wonted resting-place. The most practised 

 collector will frequently fail to distinguish the best disguised of 

 these insects, which to ordinary eyes are practically invisible. 



Mr. Wallace records his obtaining in Borneo one of the 

 " Spectres " or " Walking-stick Insects " (of the orthopterous 

 order), which was covered with foliaceous excrescences of a clear 

 olive-green colour, so as exactly to resemble a stick grown over 

 by a creeping moss or Jungermannia. Quite as marvellous an 

 imitation is the widely-known one of the " Leaf Insects " par 

 excellence, a genus of the same family, many species of which 

 occur in the islands of the Malayan Archipelago ; and it is 

 difficult to believe without close inspection that these species of 

 Phyllium are not in reality the leaves of the plants on which they 

 live. In the Kai'roo districts of this colony there occurs not 

 uncommonly a very fine Walking- Stick Phasma {Palathus 

 haivorthii), attaining a length of seven or eight inches, which in 

 its quiescent condition precisely simulates the dried-up rough 

 greyish-brown twigs of the dwarf shrubby plants characteristic of 

 the country. 



The whole order of the Orthoptera is remarkable for the 



