26 THE ENTOMOLOGIST. 



points out how very generally dwellers among leaves or grass are 

 green; instancing the parrots and green fruit-pigeons among 

 birds, the iguanas and tree snakes among reptiles, and the tree- 

 frogs among amphibians, as prominent cases of the kind. Among 

 insects numbers of species haunting herbage and foliage are 

 green, notably in such familiar groups as grasshoppers and 

 caterpillars. 



From such general adaptations to surroundings as those just 

 referred to, we may pass to that of a more specialized kind, which 

 prevails very largely throughout Nature, embracing innumerable 

 cases of more or less exact resemblance in colouring and in 

 surface to inanimate or to vegetable objects. Peculiarities of the 

 soil ; of rocks and stones on its surface ; of the bark of trees and 

 shrubs ; of mosses, lichens, and algae ; of leaves, flowers and 

 stems ; — are everywhere reproduced in the aspect of the animals 

 respectively frequenting those objects. It is when absorbed in 

 seeking or taking food, or when sleeping, that most creatures are 

 specially exposed to danger, and it is manifest what protection 

 must be afforded them by more or less similarity to the things 

 about them. 



The instances noticed are but samples of the large number 

 known amongst vertebrate animals ; and when we proceed to 

 review the vast class of insects and their allies, so numerous are 

 the cases in point that the difficulty is which to select as illus- 

 trations. The colour of the bare ground is reproduced in many 

 beetles — in South Africa notably by Curculionidce and Hetero- 

 mera,— and in a multitude of grasshoppers and locusts. Some 

 of the latter groups are exactly of the tint of the ground they 

 haunt, so that it is next to impossible to see them as long as 

 they remain motionless. The most specialized case among those 

 known to me of this kind is that of the wingless Acridian genus 

 Batrachotetrix, which has more than one representative in South 

 Africa. The best known species, B. hufo, has been dubbed the 

 " Stone Grasshopper " by Mrs. Barber, and well deserves the 

 title ; for in colouring, granulation of surface, and the singular 

 flatness of the back, it precisely resembles the small stones which 

 lie about on the surface of the ground which it frequents. In a 

 locality near Grahamstown, where this species was numerous, 

 Mrs. Barber and myself found it most difficult to detect the 

 insect, as it was remarkably sluggish, and hopped but feebly 



