IMPERFECT SOCIETIES OF INSECTS. 7 
** Some to the sun their insect wings unfold, 
Waft on the breeze, or sink in clouds of gold ; 
Transparent forms, too fine for mortal sight, 
Their fluid bodies half dissolv’d in light ; 
Loose to the wind their airy garments flew, 
Thin glitterring textures of the filmy dew, 
Dipt in the richest tincture of the skies, 
Where light disports in ever mingling dyes, 
While every beam new transient colours flings, 
Colours that change whene’er they wave their wings.” 
I wish you may have the good fortune next year to be 
a spectator of this all but celestial dance. In the mean 
time, in May and June, their season of love, you may 
often receive much gratification from observing the mo- 
tions of a countless host of little black flies of the genus 
Empis, (£. maura, ¥.) which at this period of the year 
assemble to wheel in aéry circles over stagnant waters, 
with a rush resembling that of a hasty shower driven by 
the wind. 
The next description of insect associations is of those 
that congregate for the purpose of travelling or emi- 
erating together. De Geer has given an account of the 
larvee of certain gnats (Tipula, L.) which assemble in 
considerable numbers for this purpose, so as to form a 
band of a finger’s breadth, and of from one to two yards 
in length. And, what is remarkable, while upon their 
march, which is very slow, they adhere to each other by 
a kind of glutinous secretion; but when disturbed they 
separate without difficulty?. Kuhn mentions another of 
the Tipulide (from the antennze in his figure, which is 
very indifferent, it should seem a species of agaric-gnat 
(Mycetophila), the larvee of which live in society and 
4 De Geer, vi. 338. 
