MOTIONS OF INSECTS. 467 



were still to be seen descending from above, and twinkling like stars in the 

 sun, so as to draw the attention of the most incurious. The flakes of the 

 web on this occasion hung so thick upon the hedges and trees, that baskets 

 full might have been collected. No one doubts, he observes, but that 

 these webs are the production of small spiders, which swarm in the fields 

 in fine weather in autumn, and have a power of shooting out webs from 

 their tails, so as to render themselves buoyant and lighter than the air. 1 

 In Germany these flights of gossamer appear so constantly in autumn, 

 that they are there metaphorically called " Der fliegender Sommer" (the 

 flying or departing summer) ; and authors speak of the web as often hang- 

 ing in flakes like wool on every hedge and bush throughout extensive 

 districts. 



Here we may inquire Why is the ground in these serene days covered 

 so thickly by these webs, and what becomes of them ? What occasions 

 the spiders to mount into the air, and do the same species form both the 

 terrestrial and aerial gossamer ? And what causes the webs at last to fall 

 to the earth ? I fear I cannot to all these queries return a fully satisfactory 

 answer ; but I will do the best I can. At first one would conclude, from 

 analogy, that the object of the gossamer which early in the morning is 

 spread over stubbles and fallows and sometimes so thickly as to make 

 them appear as if covered with a carpet, or rather overflown by a sea of 

 gauze, presenting, when studded with dew-drops, as I have often witnessed, 

 a most enchanting spectacle is to entrap the flies and other insects as 

 they rise into the air from their nocturnal station of repose to take their 

 diurnal flights. But Dr. Strack's observations render this very doubtful ; 

 for he kept many of the spiders that produce these webs in a large glass 

 upon turf, where they spun as when at liberty, and he could never observe 

 them attempt to catch or eat even when entangled in their webs the 

 flies and gnats with which he supplied them ; though they greedily sucked 

 water when sprinkled upon the turf, and remained lively for two months 

 without other food. 2 As the single threads shot by other spiders are 

 usually their bridges, this perhaps may be the object of the webs in ques- 

 tion; and thus the animals may be conveyed from furrow to furrow or 

 straw to straw less circuitously, and with less labour, than if they had 

 travelled over the ground. As these creatures seem so thirsty, may we not 

 conjecture that the drops of dew, with which they are always as it were 

 strung, are a secondary object with them ? So prodigious are their num- 

 bers, that sometimes every stalk of straw in the stubbles, and every clod and 

 stone in the fallows, swarms with them. Dr. Strack assures us that twenty 

 or thirty often sit upon a single straw, and that he collected about 2000 in 

 half an hour, and could have easily doubled the number had he wished it: 

 he remarks, that the cause of their escaping the notice of other observers 

 is their falling to the ground upon the least alarm. 



As to what becomes of this immense carpeting of web there are different 

 opinions. Mr. White conjectures that these threads, when first shot, might 

 be entangled in the rising dew, and so drawn up, spiders and all, by a brisk 

 evaporation, into the region where the clouds are formed. 3 But this seems 

 almost as inadmissible as that of Hooke, before related. An ingenious and 



1 Nat. Hist. i. 325. 



2 Neue Schriften der Naturforschenden Gessellschaft zu Halle, 1810, V. Heft. 



3 Xat. Hist. i. 326. 



H H 2 



