248 MEANS OF DEFENCE OF INSECTS. 
think had at that time been the electric centipede (Scolo~ 
pendra electrica, L.).—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 frequently with soap and fumed it with sul- 
phur, infected it for two days?.—Lister relates that he 
saw a spider, when upon being provoked it attempted to 
bite, emit several times small drops of very clear fluid®. 
—Mr. Briggs observed a caterpillar caught in the web 
of one of our largest spiders, by 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 produced, till the spider appeared quite exhausted °. 
—The caterpillars also of a particular tribe of saw-flies, 
remarkable for the beautiful pennated antennz of the 
males (Pteronus Jurine)*, when disturbed eject a drop 
of fluid from their mouth. Those of one species inha- 
biting the fir-tree (Pt. Pinz) 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 en- 
gaged opposite to each other on the same leaf. They 
collect in groups often of more than a hundred, and keep 
as close to each other as they can, When a branch is 
« Lesser L. -i. 284. note 6. > De Araneis 27. 
¢ 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 gathering a considerable mass of the web into 
a ball, suddenly dissolve it with fluid. He also observes, that when 
winding up a powerful prey, a spider can form its threads into a broad 
sheet. ren 
4 Jurine Hymenopt. t. vi. f. 8. 
