FOOD OF INSECTS. 265 



diverging from the centre, the threads being remote from each other. 

 These last, which in their simple state, or still more when studded with 

 dew drops, you must have a thousand times admired, are with greater 

 propriety termed nets; and the insects which form them proceeding on 

 geometrical principles may be called geometricians, while the former can 

 aspire only to the humbler denomination of weavers. I shall endeavor 

 to describe the process followed in the construction of both, beginning 

 with the latter. 



The weaving spider which is found in houses, having selected some 

 corner for the site of her web, and determined its extent, presses her spin- 

 ners against one of the walls, and thus glues to it one end of her thread. 

 She then walks along the wall to the opposite side, and there in like 

 manner fastens the other end. This thread, which is to form the outeif 

 margin or selvage of her web, and requires strength, she triples or quad- 

 ruples by a repetition of the Operation just described ; and from it she 

 draws other threads in various directions, the interstices of which she fills 

 up by running from one to the other, and connecting them by new threads 

 until the whole has assumed the gauze-like texture which we see. Books 

 of natural history, all copying from one another, have described these 

 kinds of web as fabricated of a regular warp and woof, or of parallel 

 longitudinal lines crossed at right angles by transv^erse ones glued to them 

 at the points of intersection. This, however, is clearly erroneous, as you 

 will see by the slightest examination of a web of this kind, in which no 

 such regularity of texture can be discovered. 



The webs just described present merely a simple horizontal surface, but 

 others more frequently seen in out-houses and amongst bushes possess a 

 very artificial appendage. Besides the main web, the spider carries up 

 from its edges and surface a number of single threads, often to the height 

 of many feet, joining and crossing each other in various directions. Across 

 these lines, which may be compared to the tackling of a ship, flies seem 

 unable to avoid directing their flight. The certain consequence is, that in 

 striking against these ropes they become slightly entangled, and, in their 

 endeavors to disengage themselves, rarely escape being precipitated into 

 the net spread underneath for their reception, where their doom is inevitable. 



But the net is still incomplete. It is necessary that our hunter should 

 conceal her grim visage from the game for which she lies in wait. She 

 does not, therefore, station herself upon the surface of her net, but in a 

 small silken apartment constructed below it, and completely hidden from 

 view. " In this corner," to use the quaint translation of Pliny by Phile- 

 mon Holland, Doctor in Physic^, " with what subtiltie doth she retire, 

 making semblance as though she meant nothing less than that she doth, 

 and as if she went about some other business! nay, how close lieth she, 

 that it is impossible to see whether any one be within or no !" But thus 

 removed to a distance from her net and entirely out of sight of it, how is 

 she to know when her prey is entrapped ? For this difficulty our ingenious 

 weaver has provided. She has taken care to spin several threads from the 

 edge of the net to that of her hole, which at once inform her by their 

 vibrations of the capture of a fly, and serve as a bridge on which in an 

 instant she can run to secure it. 



J L. xi. c. 24. 

 23 



