IMPERFECT SOCIETIES OF INSECTS. 291 
certain circumstances, merely for the sake of company ; again, others are 
prought together by accidental causes, and disperse when these cease to 
operate 5 and, finally, others, which may be said to form proper societies, 
are associated for the nurture of their young, and, by the union of their 
labours and instincts, for mutual society, help and comfort in erecting or 
repairing their common habitation, in collecting provisions, and in defending 
their fortress when attacked. 
With respect to the duration of the societies of insects, some last only 
during their first or larva state, and are occasionally even restricted to its 
earliest period; some again only associate in their perfect or imago state ; 
while with others, the proper societies for instance, the association is for 
life. Butif I divide societies of insects into perfect and imperfect, it will, 
I think, enable me to give you a clearer and better view of the subject. 
By perfect societies I mean those that are associated in all their states, live 
in a common habitation, and unite their labours to promote a common 
object ; and by ¢mperfect societies, those that are either associated during 
part of their existence only, or else do not dwell in a common habitation, 
nor unite their labours to promote a common object. In the present 
letter I shall confine myself to giving you some account of imperfect 
societies. 
Imperfect societies may be considered as of five descriptions : associa- 
tions for the sake of company only; associations of males during the 
season for pairing; associations formed for the purpose of travelling or 
emigrating together; associations for feeding together ; and associations 
that undertake some common work. 
The first of these associations consists chiefly of insects in their perfect 
state. The little beetles called whirlwigs (Gyrinus), which may be seen 
clustering in groups under warm banks in every river and every pool, and 
wheeling round and round with great velocity, at your approach dispersing 
and diving under water, but as soon as you retire resuming their accustomed 
Movements, seem to be under the influence of the social principle, and to 
form their assemblies for no other purpose than to enjoy together, in the 
sunbeam, the mazy dance. Impelled by the same feeling, in the very depth 
of winter, even when the earth is covered with snow, the tribes of Tipularie 
(usually, but improperly, called gnats) assemble in sheltered situations at 
mid-day, when the sun shines, and form themselves into choirs, that 
alternately rise and fall with rapid evolutions.! To see these little aéry 
beings apparently so full ofjoy and life, and feeling the entire force of the 
social principle in that dreary season, when the whole animal creation 
appears to suffer, and the rest of the insect tribes are torpid, always con- 
veys to my mind the most agreeable sensations. These little creatures 
may always be seen at all seasons amusing themselves with these choral 
dances, which Mr. Wordsworth, in one of his poems ?, has alluded to in 
the following beautiful lines : — 
“Nor wanting here to entertain the thought, 
Creatures that in communities exist 
Less, as might seem, for general guardianship 
Or through dependence upon mutual aid, 
Than by participation of delight, 
And a strict love of fellowship combined. 
bn nn Re, Oe ee ee ee ee ee SS eee 
' See also Markwick in White's Wat, Hist. ii, 266. 2 The Excursion, 
v2 
