for a dead and crumpled spot. The specimen here shown had lost one of the 

 fronds from its right side. (These caterpillars are said to shed their fronds 

 and weave them into their cocoons.) (Fig. S, Nos. i, 2 and 3.) 



Class VI. Highly developed color -and- pattern mimicry, scarcely aided by 

 modifications of form, of a detail of the caterpillar's usual inanimate surround- 

 ings (Fig. T.). The plants on which this late-developing sphinx larva 

 commonly feeds, bear, almost invariably, at that season, a few black dead 

 leaves, frost-bitten or otherwise wilted — and the caterpillar, hanging head 

 downward, is a close counterfeit of one of these. The imitation is very close 

 indeed, — even the usual dark hole at the bottom of such a leaf being rendered 

 by the black spot on the caterpillar's head, intensified by the encircling white,* 

 and the vein-markings being accurately copied by diagonal stripes and fine 

 reticulations. The tail-horn, which this larva has in common with most 

 sphinx caterpillars, here serves to counterfeit a leaf-stem, the midrib continu- 

 ation of which through the leaf is closely imitated on the caterpillar by a pro- 

 nounced light line. These markings and details of form are largely the same 

 as those found on obliteratively shaded sphinx larvae, where they serve the 

 same general purpose of leaf-stem and vein imitation; but the present 

 case, being one of pure and simple mimicry, allows of a clearer and more 

 definite development of these details. Notice this caterpillar's complete 

 lack of light-and-shade gradation. He is equipped, not to be unapparent 

 as a solid object, and to merge with the details of his average background, 

 but to appear to be another kind of definite, rotund body than such as he 

 really is. 



Class VII. Compound mimicry of normal inanimate surroundings, coupled 

 with an element of background-picturing. (Plate XVI, Fig. U.) This cater- 

 pillar's several light-colored longitudinal stripes resolve themselves into the 

 appearance of separate needles of the white pine tuft in which it feeds. But 

 the darker and broader green stripes (sometimes partly dark red) then pass 

 for the general background of needles, against which the light stripes show as 



* See Chapter XX, p. 125; Chapter XXII, p. 157, and Fig. 120. 



195 



