94 The Colours of Animals. 



eye-spots and the faint lateral line mean ? and why 

 are some green and some brown, offering thus such 

 a marked contrast to the leaves of the small epilobe 

 on which they feed ? Other questions will suggest 

 themselves later. I must now call your attention 

 to the fact that, when the caterpillars first quit the 

 egg, and come into the world (fig. 14), they are 



Fig. 14. The Caterpillar of the ELEPHANT HAWK-MOTH 

 (Charocampa elfenor). First Stage. 



quite different in appearance, being, like so many 

 other small caterpillars, bright green, and almost 

 exactly the colour of the leaves on which they feed. 

 That this colour is not the necessary or direct con- 

 sequence of the food, we see from the case of 

 quadrupeds, which, as I need scarcely say, are never 

 green. It is, however, so obviously a protection to 

 small caterpillars, that this explanation of their 

 green colour suggests itself to every one. 



3. After five or six days, and when they are about 

 a quarter of an inch in length, they go through their 

 first moult. In their second stage (fig. 15), they have 

 two white lines, stretching along the body from the 

 horn to the head; and after a few days (fig. 16), 

 but not at first, traces of the eye-spots appear on 

 the fourth and fifth segments, shown by a slight 



