hozi) Spiders effect their aerial Excursions. 451 



complicated structure, resembling ravelled silk of the finest qua- 

 lity and clearest white. They were of various shapes and di- 

 mensions, some of the largest measuring upward of a yard in 

 length, and several inches in breadth in the widest part ; while 

 others were almost as broad as long, presenting an area of a few 

 square inches ovày. 



These webs, it was quickly perceived, were not formed in the 

 air, as is generally believed, but at the earth's surface. 'J he 

 lines of whicli they were composed being brought into contact 

 by the mechanical action of gentle airs, adhered together, till by 

 continual additions they were accumulated into flakes or masses 

 of considerable magnitude, on which the ascending current, 

 occasioned by the rarefaction of the air contiguous to the heated 

 ground, acted with so much force as to separate them from the 

 objects to which they were attached, raising them in the atmo- 

 sphere to a perpendicular height of at least several hundred 

 feet. I collected a number of these webs about mid-day as they 

 rose, and again in the afternoon, when the upward current had 

 ceased and they were falling, but scarcely one in twenty con- 

 tained a spider ; though on minute inspection I found small 

 winged insects, chietly aphides, entangled in most of them. 



From contemplating this unusual display of gossamer, my 

 thoughts were naturally directed to the animals which produced 

 it ; and the countless myriads in which they swarmed almost 

 created as much surprise as the singular occupation that en- 

 grossed them. Apparently actuated by the same impulse, all 

 were intent upon traversing the regions of air ; accordingly, 

 after gaining the summits of various objects, as blades of grass, 

 stubble, rails, gates, &c., by the slow and laborious process of 

 climbing, they raised themselves still higher by straightening 

 their limbs ; and elevating the abdomen, by bringing it from the 



usual 



