PEOTECTIVE AND AGGRESSIVE MIMICRY 259 



prominent. The effect is greatly heightened by the 

 suddenness of the transformation, which endows an 

 innocent-looking and inconspicuous animal with a 

 terrifying and serpent-hke appearance. I well re- 

 member the start with which I drew back my hand 

 as I was going to take the first specimen of this cater- 

 pillar that I had ever seen. The appearance of the 

 closely allied C. porcellus in the alarming attitude is 

 shown in fig. 56. The posterior ' eyes ' are insignifi- 

 cant in this species. 



Fig. 56.— The caterpillar of the Small Elephant Hawk Moth ( Chcerocampa porcellus) 

 in its terrilyin? attitude after being disturbed (from Weismann) ; stage iv. ; 

 about twice natural size. 



Such caterpillars terrify their enemies by the sug- 

 gestion of a cobra-like serpent ; for the head of a 

 snake is not large, while its eyes are small and not 

 specially conspicuous. The cobra, however, inspires V 

 alarm by the large eye-like ' spectacles ' upon the dilated • • 

 hood, and thus offers an appropriate model for the v 

 swollen anterior end of the caterpillar with its terrify- , < 

 ing markings. It is extremely interesting that the 

 caterpillar should thus mimic a feature which is only 

 deceptive in the snake itself. 



