MOTIONS OF INSECTS. 341 



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

 hanging 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 fal- 

 lows — 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 observa- 

 tions 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^. As the 

 single threads shot by other spiders are usually their 

 bridges, this perhaps may be the object of the webs in 



* Neur- Sr/irif'en ilrr Nidnrfnrschtnikn Gt^'iellschaft zu Halle 1810. v. 



