n.] TYPES OF COLOURING. 63 



are particularly suitable, "because they live an exposed 

 life; because the different species; even of the same genus, 

 often feed on different plants, and are therefore exposed to 

 different conditions ; and last, not least, because we know 

 more about the larvae of the Lepidoptera than about those 

 of any other insects. The larvae of ants all live in 

 the dark ; they are fed by the perfect ants, and being 

 therefore all subject to very similar conditions, are all 

 very much alike. It would puzzle even a good naturalist 

 to determine the species of an ant larva, while, as we 

 all know, the caterpillars of butterflies and moths are 

 as easy to distinguish as the perfect insects ; they differ 

 from one another as much as, sometimes more than, the 

 butterflies and moths themselves. 



There are five principal types of colouring among 

 caterpillars. Those which live inside wood, or leaves, 

 or underground, are generally of a uniform pale hue ; 

 the small leaf- eating caterpillars are green, like the leaves 

 on which they feed. The other three types may, to 

 compare small things with great, be likened to the three 

 types of colouring among cats. There are the ground 

 cats, such as the lion or puma, which are brownish or 

 sand colour, like the open places they frequent. So also 

 caterpillars which conceal themselves by day at the 

 roots of their food-plant tend, as we have seen, even if 

 originally green, to assume the colour of earth. Nor 

 must I omit to mention the Geometridce, to which I have 

 already referred, and which, from their brown colour, 

 their peculiar attitudes, and the frequent presence of 

 warts or protuberances, closely mimic bits of dry stick. 

 That the caterpillars of these species were originally 

 green, we may infer from the fact that some of them 



