420 MEANS OF DEFENCE OF INSECTS. 



think had at that time been the electric centipede (Geopkilus electricus.) 

 Lesser having once touched the anal horn of the caterpillar of some 

 sphinx, suddenly turning its head round it vomited upon his hand a quan- 

 tity of green viscous and very fetid fluid, which, though he washed it fre- 

 quently with soap and fumed it with sulphur, infected it for two days. 1 

 Lister relates that he saw a spider, when upon being provoked it attempted 

 to bite, emit several times small drops of very clear fluid. 2 Mr. Briggs 

 observed a caterpillar caught in the web of one of our largest spiders, bv 

 means of a fluid which it sent forth, entirely dissolve the great breadth of 

 threads with which the latter endeavoured to envelop it, as fast as pro- 

 duced, till the spider appeared quite exhausted. 3 The caterpillars also of 

 a particular tribe of saw-flies, remarkable for the beautiful pennated 

 antennae of the males (Pteronus)*, when disturbed, eject a drop of fluid 

 from their mouth. Those of one species inhabiting the fir-tree (Pt. Pini) 

 are ordinarily stationed on the narrow leaves of that tree which they 

 devour most voraciously in the manner that we eat radishes with their 

 head towards the point. Sometimes two are engaged opposite to each 

 other on the same leaf. They collect in groups often of more than a hun- 

 dred, and keep as close to each other as they can. When a branch is 

 stripped they all move together to another. If one of these caterpillars 

 be touched or disturbed, it immediately with a twist lifts the anterior part 

 of its body, and emits from its mouth a drop of clear resin, perfectly simi- 

 lar both in odour and consistence to that of the fir. 5 What is still more 

 remarkable, no sooner does a single individual of the group give itself this 

 motion, than all the rest, as if they were moved by a spring, instantaneously 

 do the same. 6 Thus these animals fire a volley, as it were, at their annoy- 

 ers, the scent of which is probably sufficient to discomfit any ichneumons, 

 flies, or predaceous beetles that may be desirous of attacking them. 



Amongst those which annoy their enemies by the emission of fluids from 

 their anus are the larger Carabi. These, if roughly handled, will spirt to 

 a considerable distance an acrid, caustic, stinking liquor, which, if it 

 touch the eyes or the lips, occasions considerable pain. 7 The rose- 

 scented Capricorn (Cerambyx moschatus) produced a similar effect upon 

 Mr. Sheppard by similar means. The fluid in this had a powerful odour 

 of musk. The acid of ants has long been celebrated, and is one of their 

 most powerful means of defence. When the species that have no sting 

 make a wound with their jaws, they insinuate into it some of this acid, the 

 effluvia produced by which are so subtile and penetrating, that it is impos- 

 sible to hold your head near the nest of the hill-ant (Formica rufa), when 

 the ants are much disturbed, without being almost suffocated. This odour 

 thus proceeding from myriads of ants is powerful enough, it is said, to kill 



1 Lesser, 1. i. 284. note 6. 



2 De Araneis, 27. 



s This gentleman is of opinion that spiders possess the means of re-dissolving 

 their webs. He observed one, when its net was broken, run up its thread, and 



fathering a considerable mass of the web into a ball, suddenly dissolve it with fluid. 

 Ie also observes that, when winding up a powerful prey, a spider can form its 

 threads into a broad sheet. 

 4 Jurine, Hymenopt. t. vi. f. 8. 

 * De Geer, ii. 971. 



6 1 owe the knowledge of this circumstance to Mr. MacLeay. 



7 De Geer, iv. 86. Geoffr. i. 141. 



