STATES OF INSECTS. 149 



ral, done by the ingenious Mr. Abbott of Georgia, in 

 which this part is well exhibited a . 



Another small caterpillar, as it should seem, of a geo- 

 meter, prepared by the same gentleman, exhibits a pair 

 of similar horns on the fifth and sixth segments : in these 

 the common base from which the fork proceeds is very 

 short and wide, and each branch grows gradually more 

 slender from the base to the apex, where it is involute. 

 Whether these are retractile, or whether they correspond 

 with those of P. Machaon in their nature and use, cannot 

 be ascertained from a dead specimen : as they belong to a 

 larva of a quite different tribe of Lepidoptera, the proba- 

 bility is, that they essentially differ. Two globose re- 

 tractile vesicles issue from the ninth and tenth segments 

 of those of Arctia chrysorrhea, &c. b 



A great number of Lepidopterous larvae, particularly 

 those which are smooth and of a moderate size, have be- 

 tween the under-lip and fore-legs a slender transverse open- 

 ing, containing a teat-like protuberance of the same con- 

 struction as the furcate horn of the caterpillar of the beau- 

 tiful mountain-butterfly, Parnassius Apollo ; and, like that, 

 can either be wholly retracted and concealed, or by pres- 

 sure be extended to the length of one of the legs. In some 

 larvae this part is of a subhemispherical figure, generally 

 single, but sometimes double. It is commonly, however, 

 more slender and conical ; and when of this shape, it is 

 sometimes quadruple c . The use of this part is not very 

 clearly known : some have supposed it to be a second 

 spinneret, and to be of use in fabricating the cocoon ; but 



* This gentleman was remarkable for the admirable manner in 

 which he prepared caterpillars, so as scarcely to differ from life, 

 b Reaum. i. 92, c Bonnet ii. 84—, iii. 1, 



