FOOD OF INSECTS. 409 



small silken apartment constructed below it, and com- 

 pletely hidden from view. " In this corner," to use the 

 quaint translation of Pliny by Philemon Holland, Doctor 

 in Physic*, "with what subtiltie doth she retire making 

 semblance as though she meant nothino- 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 entrapjDcd ? 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. 



You will readily conceive that the geometrical spiders, 

 in foj'ming their concentric circled nets, follow a process 

 very different from that just described, than which in- 

 deed it is in many respects more curious. As the net is 

 usually fixed in a perpendicular or somewhat oblique di- 

 rection, in an opening between the leaves of some shrub 

 or plant, it is obvious that round its whole extent will 

 be required lines to which can be attached those ends of 

 the radii that are furthest from the centre. Accordingly 

 the construction of these exterior lines is the spider's first 

 operation. She seems careless about the shape of the 

 area which they inclose, well aware that she can as 

 readily inscribe a circle in a triangle as in a square, and 

 in this respect she is guided by the distance or proximity 

 of the points to which she can attach them. She si)ares 

 no pains, however, to strengthen and keep them in a 

 => L. xi. c. ^4. 



