4:4 PERFECT SOCIETIES OF INSECTS. 
gum-arabic. These insects seem to be furnished with 
an acid of a very penetrating odour, which perhaps is 
useful to them for softening the wood. The soldiers 
in these societies are as about one to twenty-five of the 
labourers®, The anonymous author of the observa- 
tions on the Termites of Ceylon seems to have disco- 
vered a sentry-box in his nests. “I found,” says he, 
‘in a very small cell in the middle of the solid mass, 
(a cell about half an inch in height, and very narrow,) 
a larva with an enormous head.—Two of these indivi- 
duals were in the same cell:—one of the two seemed 
placed as sentinel at the entrance of the cell. I amused 
myself by forcing the door two or three times ;—the 
sentinel immediately appeared, and only retreated when 
the door was on the point to be stopped up, which was 
done in three minutes by the labourers.” 
I hope this account has reconciled you in some de- 
eree to the destructive ‘Termites:—I shall next intro- 
duce you to social insects, concerning most of which 
you have probably conceived a more favourable opi- 
nion ;—I mean those which constitute the second class 
of perfect societies, whose workers are not larvae, but 
neuters. These all belong to the Hymenoptera order 
of Linné :—there are four kinds of insects in this order, 
(which you will find as fertile in the instructors of man- 
kind, as you have seen it to be in our benefactors, ) that, 
varying considerably from each other in their proceed- 
ings as social animals, separately merit your attention : 
namely, ants, wasps and hornets, humble-bees, and the 
hive-bee. I begin with the first. 
@ Latr. Hist, Nat. xiii. 64. » Dict. Hist. Nat. xxii, 57, 58. 
