274 



MOTIONS OF INSECTS. 



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 meta- 

 phorically called " Der Jiiegender Sommer " (the flying or 

 departing summer) ; and authors speak of the web as often 

 hanging in flakes like wool on every hedge and bush through- 

 out 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 ap- 

 pear 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 question ; and thus the animals may 

 be conveyed from furrow to furrow or straw to straw less 



1 Nat. Hist. i. 325. 



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



