MEANS or DEFENCE OF INSECTS. 255 



mies. — Dr. Arnold has made a curious observation 

 (confirmed by Di\ Forsstrom with respect to others of 

 the genus) on the use of the long processes or tails that 

 distinguish the secondary wing^> of Hesperia larbm. 

 These processes, he remarks, resemble antennae, and 

 when the butterfly is sitting it keeps them in constant 

 motion; so that at first sight it appears to have a head 

 at each extremity ; which deception is much increased 

 by a spot resembling an eye at the base of the processes. 

 These insects, perhaps, thus perplex or alarm their as- 

 sailants. — Goedart pretended that the anal horn with 

 which the catei'pillars of so many hawk-moths (Sphbix) 

 are armed, answers the end of a sting instilling a dan- 

 gerous venom : but the observations of modern ento- 

 mologists have proved that this is altogether fabulous, 

 since the animal has not the povs'er of moving them^ 

 Their use is still unknown. 



Whether the long and often tremendous horns on 

 the head, thorax, and even elytra, with which many in- 

 sects are armed, are beneficial to them in the view 

 under consideration, is very uncertain. They are often 

 sexual distinctions, and have a reference probably 

 rather to sexual purposes and the economy of the ani- 

 mal, than to any thing else. They may, however, in 

 ?ome instances deter enemies from attacking them, and 

 therefore it was right not to omit tliem wholly, though 

 I shall not further enlarge upon them. — Their mandi- 

 bles or upper jaws, though principally intended for 

 mastication, — and in the case of the Hymcnoptera^ as 

 instruments for various economical and mechanical 

 uses, — are often employed to annoy their enemies or 



" De Gcer, i. 149— 



