148 NATURE SKETCHES IN TEMPERATE AMERICA 



forms may possibly have descended. Moreover, in the hot 

 regions there is a great abundance of bush snakes and hzards 

 which they might resemble, and if this is so there is a real 

 mimetic connection here which our temperate forms do not 

 seem to show. While full-grown larvae of the swallow-tail 

 seem to show recent adaptations, such as eye-spots, yet some 

 of its peculiarities may have been handed down from a remote 

 past. Many of these cases of mimicry are problematical. 



Poulton describes a species of large elephant hawk-moth 

 somewhat common in England which may be classed in the 

 same category as the tiger caterpillar as regards its terrifying 

 markings. In this cateri>illar the eye-like markings occur on 

 each side of two of the forward body rings. It lives on the 

 great willow herb. As soon as the leaves are rustled by an 

 approaching enemy, the caterpillar swiftly draws its head and 

 first three segments into the next two rings bearing the eye-like 

 spots, giving to these rings a swollen appearance and resembling 

 the head of an animal upon wliicli four enormous, terrii)le looking 

 eyes are prominent. The effect "is greatly heightened by the 

 suddenness of the transformation, which endows an innocent 

 looking and inconsj)icuous animal with a terrifying and serpent- 

 like appearance." 



In another species of caterpillar, C. porcellufi, the eye-like 

 spots are also conspicuous and Poulton says of this sj)ecies 

 that such caterpillars terrify their enemies by the suggestion 

 of a cobra-like serpent, for the head of a snake is not large, 

 while the eyes are small and not especially conspicuous. The 

 cobra, however, inspires alarm by the large eye-like "spectacles" 

 upon the dilated hood, and thus offers an appropriate model 

 for the swollen anterior end of the caterpillar with its terrifying 

 markings. It is notew^orthy that the caterpillar should thus 

 mimic a feature which is only deceptive in the snake itself. 

 Bates has described a South American caterpillar, which startled 

 him and every one to whom he showed it, by its strong 

 resemblance to a snake, and it even possessed the features 

 which are characteristic of a poisonous .serpent. 



An amusing incident relative to the nearly allied species, 

 the troilus butterfly caterpillar, may be of interest in this 

 connection. A neighbor was nmch annoyed by the depreda- 



