MOTIONS OF INSECTS. 335 



substance which, after a fbgg, may be observed to fly 

 up and down the air : catching several of these, and ex- 

 amining them with my microscope, 1 found them to be 

 much of the same form, looking- most like to a flake of 

 worsted prepared to be spun ; though by what means 

 they should be generated or produced is not easily ima- 

 gined : they were of the same weight, or very little 

 heavier than the air ; and ^tis not unlikcli/^ but that 

 those great white clouds^ thai appear all the summertime^ 

 may he of the same substance^.'''' So liable are even the 

 wisest men to error when, leaving fact and experiment, 

 they follow the guidance of fancy. Some French na- 

 turalists have supposed that these Fils de la Vierge^ as 

 they are called in France, are composed of the cot- 

 tony matter in which the eggs of the Coccus of the vine 

 (C Vitis, L.) are enveloped **. In a country abound- 

 ing 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 conservatory, it will not at all account for i}ie 

 phaenomenon. — What will you say, if I tell you that 

 these webs (at least many of them) are air-balloons — 

 and that the aeronauts are not 



" Lovers who may bestride the gossamer 

 That idles in the wanton summer air, 

 And yai not fall" — 



hut spiders, who long before Montgolfier, nay, ever since 



• Microgr. 202. It has been objected to an excellent primitive uriter 

 {Clemens Romanus), that he believed the absurd fable of the phoenix. 

 But surely this may be allowed for in him, who was no naturalist, when 

 a scientific natural philosoplicr could believe that the clouds arc made of 

 spiders web ! " Latmille, Hiit. Nat. xii. 388, 



