MOTIONS OF INSECTS. 499 



to error, when leaving fact and experiment, they follow the guidance of 

 fancy. Some French naturalists have supposed that these Jils de la 

 Vierge, as they are called, are composed of the cottony matter in which 

 the eggs of the Coccus of the vine (C. Vitis) 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-gardeo, 

 and the Coccus seldom seen out of the conservatory, it will not at all 

 account for the phenomenon. What will you say, if I tell you that 

 these webs (at least many of them) are air-balloons, and that the aero- 

 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 seems to have been suspected long ago by Henry 

 Moore, who says, 



" As light and thin as cobwebs that do fly 



In the blew air, caus'd by the autumnal sun, 



That .boils the dew that on the earth doth lie, 



May seem this whitish rag then is the scum ; 

 Unless thai wiser men make't the field-spider' s loom .-"^ 



where he also alludes to the old opinion of scorched dew. But the 

 first naturalists who made this discovery appear to have been Dr. Hulse 

 and Dr. Martin Lister — the former first observing that spiders shoot their 

 webs into the air ; and the latter, besides this, that they were carried 

 upon them in that element."^ This last gentleman, in fine serene weather 

 in September, had noticed these webs falling from the heavens, and in 

 them discovered more than once a spider, which he named the hird. 

 On another occasion, whilst he was watching the proceedings of a com- 

 mon spider, the animal, suddenly turning upon its back and elevating 

 its anus, darted forth a long thread, and vaulting from the place on 

 which it stood was carried upwards to a considerable height. Numerous 

 observations afterwards confirmed this extraordinary fact ; and he further 

 discovered that while they fly in this manner, they pull in their long 

 thread with their fore feet, so as to form it into a ball — or, as we may 

 call it, air-balloon — of flake. The height to which spiders will thus 

 ascend he affirms is prodigious. One day in the autumn, when the air 

 was full of webs, he mounted to the top of the highest steeple of York 

 minster, from whence he could discern the floating webs still very high 

 above him. Some spiders that fell and were entangled upon the pin- 

 nacles he took. They were of a kind that never enter houses, and 

 therefore could not be supposed to have taken their flight from the 

 steeple.'* It appears from his observations that this faculty is not con- 

 fined to one species of spider, but is common to several, though only in 



> Latreille, Hist. Nat. xii. 388. * Quoted in the Athenceum, v. 126. 



» Ray's Letters, 3rt. 69. 



* Ray's Letters, 37. 87. Lister, De Aran. 80. Lister illustrates the force with which 

 these creatures shoot their thread, by a homely though very forcible simile: "Resupinata 

 (says he) anura in ventum dedit, filumque ejaculala est quo plane mode robustissimus 

 juvenise distentissima vesica urinam." 



