340 INSECT ARCHITECTURE. 



spiders, seeing that they are destitute of wings, \ 

 transport themselves from tree to tree, across brooks, | 

 and frequently through the air itself, without any ap- j 

 parent starting point. On looking into the authors j 

 who have treated upon this subject, it is surprisinor 

 how little there is to be met with that is new, even in ■ 

 the most recent. Their conclusions, or rather their i 

 conjectural opinions, are, however, worthy of noticej 

 for, by unlearning error, we the more firmly esta- ] 

 blish truth. • 



1 . One of the earliest notions upon this subject i 

 is that of Blancanus, the commentator on Aristotle, 

 which is partly adopted by Redi, by Henricus i 

 Regius of Utrecht by Swammerdam,* by Leh- , 

 mann the mineralogist, and Kirby and Spenccf ; 

 " The spider's thread," says Swammerdam, " is 

 generally niade up of two or more parts, and 

 after descending by such a thread, it ascends by 

 one only, and is thus enabled to waft itself from ' 

 one height or tree to another, even across running 

 waters; the thread it leaves loose behind it being 

 driven about by the wind, and so fixed to some 

 other body." " I placed," says Kirby, "the large i 

 garden spider (^Epeira diadema) upon a stick i 

 about a foot long, set upright in a vessel containing 



water It let itself drop, not by a single thread, j 



but by two, each distant from the other, about the ^ 

 twelfth of an inch, guided, as usual, by one of its hind | 

 feet, and one apparently smaller than the other. ; 

 When it had suffered itself to descend nearly to the 

 surface of the water, it stopped short, and by some 

 means, which I could not distinctly see, broke off, I 

 close to the spinners, the smallest thread, which still 

 adhering by the other end to the top of the stick, 



* Swammerdam, part i. p. 24. ; 



+ Intr. j. vol. p. 415. i 



