348 INSECT ARCHITECTURE. 



lov/ing details are given in confirmation of this 

 opinion. Mr Blackwall observed, the 1st Oct., 1826, 

 a little before noon, with the sun shining brightly, 

 no wind stirring, and the thermometer in the shade 

 ranging from 5o°.5 to 64°, a profusion of shining 

 lines crossing each other at every angle, forming a con- 

 fused 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 phenomenon, 

 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 wliite; they were of various shapes and 

 dimensions, 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 



