52 ON PLANTS AND INSECTS. [LECT. 



hues of the Death's-head hawk-moth caterpillar, which 

 feeds on the potato, unite so beautifully the brown of the 

 earth, the yellow and green of the leaves, and the blue 

 of the flowers, that, in spite of its size, it can scarcely be 

 perceived unless the eye be focussed exactly upon it. 



Chcerocampa nerii is also an interesting case. Many of 

 the hawk-moth caterpillars have eye-like spots, to which 

 I shall have to allude again presently. These arc gene- 

 rally reddish or yellowish, but in Ch. nerii, which feeds 

 on the periwinkle, they are bright blue, and in form as 

 well as colour closely resemble the blue petals of that 

 flower. Ch. celerio also has two smaller blue spots, 

 with reference to which I ca'n make no suggestion. It 

 is a very rare species, and I have never seen it. Pos- 

 sibly, in this case, the blue spots may be an inherited 

 character. 



No one who looks at any representations of hawk- 

 moth caterpillars can fail to be struck by the peculiar 

 colouring of those belonging to the genus Anceryx, 

 which differ in style of colouring from all other sphinx 

 larvae, having longitudinal bands of brown and green. 

 Why is this ? Their habitat is different. They feed on 

 the leaves of the pinaster, and their peculiar colouring 

 offers a general similarity to the brown twigs and narrow 

 green leaves of a conifer. There are not many species of 

 Lepidoptera which feed on the pine, but there are a 

 few ; such, for instance, are Achatia spreta and Dendro- 

 lirnus pini, both of which have a very analogous style of 

 colouring to that of Anceryx, while the latter has also 

 tufts of bluish-green hair which singularly mimic the 

 leaves of the pine. It is still more remarkable that in a 

 different order of insects, that of the Hymenoptera, we 



