348 INSECT ARCH1TECTVRE. 



confused net-work, covering the fields and hedges, 

 and thickly coating his feet and ankles, as he walked 

 across a pasture. He was more struck with the phe- 

 nomenon, because on the previous day a strong gale 

 of wind had blown from the south, and as gossamer 

 is only seen in calm weather, it must have been all 

 produced within a very short time. 



" What more particularly arrested my attention," 

 says Mr. Blackwall, " was the ascent of an amazing 

 quantity of webs, of an irregular, complicated struc- 

 ture, resembling ravelled silk of the finest quality, and 

 clearest white ; they were of various shapes and di- 

 mensions, some of the largest measuring upwards 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 only. 



" These webs, it was quickly perceived, were not 

 formed in the air, as is generally believed, but at the 

 earth's surface. The lines of which they were com- 

 posed, being brought into contact by the mechanical 

 action of gentle airs, adhered together, till, by con- 

 tinual 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 

 atmosphere 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, chiefly aphides, entangled 

 in most of them. 



" From contemplating this unusual display of 

 gossamer, my thoughts were naturally directed to 



