HETEROCERA HAWK-MOTHS 



331 



tip with a tuft, or with two tufts, of dense, long scales, capable 

 of expansion. 



The larvae are remarkable for their colours and form. Tbe 

 anterior segments are attenuated, but are capable of great retrac- 

 tion, so that in repose (Fig. 190, A) this shape is concealed by 

 the curious attitudes that are assumed. There is in nearly 

 all cases a conspicuous horn on the eleventh segment, and the body 

 at the extremity behind the horn is so much modified that the 

 terminal two segments look like little more than a pair of large 

 claspers. In the Choerocampini, the thoracic segments are 

 retractile, and can be withdrawn into the more or less inflated 

 fourth segment, and give the creature somewhat the appearance 



FIG. 190. Larva of 

 the Poplar Hawk- 

 moth, Smerinthus 

 popvM. x 1. A, 

 in repose ; B, in 

 movement. 



of a miniature hooded snake. The larvae of Sphingidae do not 

 bear any conspicuous hairs except during the first instar. They 

 do not spin cocoons, but bury themselves in the earth. The 

 pupa is remarkable from the deep cleft that exists to admit air 

 to the first spiracle, and for a deep depression on each side of the 

 anterior part of abdominal segments 5-7 ; in some cases the 

 proboscis projects on the breast somewhat like the handle of a 

 pitcher. 



A great deal has been written on the colours, markings, and 

 attitudes of Sphingid larvae, and many interesting facts have 

 been brought to light. We may refer the reader to the writings 

 of Weismann * and Poulton, 2 without, however, recommending 

 him to place an implicit confidence in their somewhat 

 metaphysical disquisitions ; for the views there shadowed will 



1 Studies in the Theory of Descent, part 2, London, 1881. 

 - Tr. ent. Soc. London, 1885 aiid 1886. 



