322 On the Mantifr in which 



dcr only prefTes it a little, or nioiftens it with a drop of it3 

 vifcous liquid. 



But tlieic webs arc commonly found in forefts and woods, 

 often on the high branches of different trees, not unfrcquently 

 fu'pended between the roofs of different houfes ftanding near 

 each other, and even often extended over ftreams and ponds 

 of water, fo that it is inipoflible to conceive how the fpider 

 could proceed from the one point to the other, in order to 

 eflablifli her lirft thread, and to faftcn to it the ditl'ercnt ra- 

 dii. Some have endeavoured to account for this circum- 

 ftance by the mofl lingular fuppofitions, as is commonly the 

 cafe when philolophers attempt to explain the phasnomena 

 ot nature before they have examined them with fuflicient ac- 

 curacy; but I fliall not liere trouble the reader with ihefe 

 hypothefes, which conti^adift themfclves *. Accident, to 

 which we are indebted for mofi of our difcoveries, particu- 

 larly in natural hiftory, though we are unuilling to allow 

 it any fhare in our difcoveries, gave me an opportunity of 

 making an obfervation which decides the above queftion. On 

 a w^arm funmier's evening I law a crofs-fpider (aranen di- 

 adcvia) let herlelf fpeedily down from a branch of a tree by 

 her ulual thread; and at the fame time a multitude of fimilar 

 threads, which had their origin at the fame place as the 

 other, floated around; while the air, which was not percep- 

 tibie to my fenies, carried them to a conliderable diftance, 

 and even a conliderable height. Though I approached with the 

 utmolt gentlenefs, the direftion of the floating threads was 

 immediately changed, and in a moment thev had reached a 

 neighbouring branch, to which they adhered. The fpider 

 foon obferved thnt her floating threads had reached a fixed 

 point, and inmicdiatelv clambered up to them, having thus 

 given me an opportunity of I'eeing the fecret of the com- 

 mencement of her ingenious labour. Guided by this trace, 

 it was now eafy for me to make my obfervatiouii with greater 

 accuracy; and the refult of them is as follows. When a 

 fpider is dcfirous of proceeding to a diliant place, flie fud- 

 denly lets herlelf down by a pretty ftrong thread, and at the 

 fame time draws one of her hind legs ovtr the glandular 

 parts which contain the materials of her web. By theie means 

 fhe forces from them a great number of fmall threads, and 

 configns them to the air; which, on account of their fpe- 

 cific lightnefsj makes them float, fo that they remain at that 



* I Ihall only mention one. — Lifter in his HijL Animal. Angliee, which 

 Contains a great niunv important obfer\'ations on fpidcrs, explains this, 

 p. -, as an i}acul,\:io lilorum, and endeavours to make it more evident, by 

 comparing it to tht manner Ja which the fun tniit> his rays. 



4 height 



