MOTIONS OF INSECTS. 335 
same form, looking most like to a flake of worsted pre- 
pared to be spun; though by what means they should 
be generated or produced is not easily imagined: they 
were of the same weight, or very little heavier than the 
air; and ’tis not unlikely, but that those great white 
clouds, that appear all the summer time, may be of the 
same substance*.” So liable are even the wisest men 
to error when, leaving fact and experiment, they fol- 
low the guidance of fancy. Some French naturalists 
have supposed that these fils de la Vierge, as they are 
called in France, are composed of the cottony matter in 
which the eggs of the Coccus of the vine (C. Vitis, L.) 
are enveloped>. In a country abounding in vineyards 
this supposition would not be absurd; but in one like 
Britain, in which the vine is confined to the fruit- 
garden, and the Coccus seldom seen out of the conser- 
vatory, it will not at all account for the phznomenon. 
What will you say, if I tell you that these webs (at 
least many of them) are air-balloons—and that the aéro- 
nauts are not 
** Lovers who may bestride the gossamer 
That idles in the wanton summer air, 
And yet not fall”— 
but spiders, who long before Montgolfier, nay, ever since 
the creation, have been in the habit of sailing through 
the fields of ether in these air-light chariots! This 
* Microgr. 202. It has been objected to an excellent primitive 
writer (Clemens Romanus), that he believed the absurd fable of the 
pheenix. But surely this may be allowed for in him, who was no na- 
turalist, when a scientific natural philosopher could believe that the 
clouds are made of spiders web ! 
> Latreille, Hist. Nat, xii. 388. 
