70 INTRODUCTION. 



the foot, is dilated, these claws are turned outwards, 

 and their small curved points find inequalities to 

 which they can adhere even on a surface which might 

 appear to the naked eye almost smooth. Several 

 modifications of this curious prehensile foot occur 

 among the larvae of various kinds of moths ; but of 

 these it forms no part of our present purpose to give 

 an account. (Plate II. fig. 2, Represents the pro- 

 leg of the caterpillar of a butterfly, from Reaumur. 

 Fig. 3, A pair of pro-legs, shewing the manner in 

 which they cling to a branch). 



The head of caterpillars is of a harder*consistence 

 than the rest of the body, and in most cases seems 

 to be composed of two oval lobes united* In that 

 of the Purple Highflier, these lobes are produced be- 

 hind into two rather long occipital horns. (Plate III, 

 fig. 6). The conformation of the mouth of lepidop- 

 terous larvae in general, bears considerable resem- 

 blance to that of several masticating insects in their 

 perfect state. See Plate II. fig. 4, which represents 

 the under side of the head of a caterpillar.) It con- 

 sists of an upper lip, with a deep notch in the centre 

 (b) ; two strong mandibles divided at the tip into 

 numerous sharp teeth, which cut the leaves that 

 serve as food (c 9 c) ; two small and indistinct organs 

 of a soft consistence, lying under the mandibles, 

 which may be regarded as the maxillce ; and an un- 

 der lip (d). Near the summit of the latter, which 

 is usually of a pyramidal shape, is placed, according 

 to Reaumur, a small conical protuberance, perforated 



