116 0/1 JYorth American Spiders. 



Miscellaneous Retnarks and Citations. 



The subject examined, so sagaciously, one hundred and sixteen 

 years ago, by the philosophical child, remains nearly as he left it. 

 Other and recent writers also adopt the hypothesis of the ascent of 

 the thread of the flying spider, in consequence of the supposed in- 

 ferior specific gravity of its web. It is however obvious that spi- 

 ders' webs of all sorts are in fact specifically heavier than the at- 

 mosphere, and under given circumstances fall in that medium ; of 

 course they cannot, from mere inherent levity, rise in the air, and 

 much less raise any weight attached to them. Upward currents in 

 the atmosphere, when they exist, will it is true account for the as- 

 cent of the web, and it may perhaps ascend with sufficient power to 

 elevate the spider. There is, however, under given circumstances, 

 a remarkable constancy in the power exerted by this insect, in caus- 

 ing his own web to become buoyant, and often to such a degree 

 that he mounts, sometimes, many hundred feet into the air, above 

 th© trees, and towers, and steeple tops, and he rides there with more 

 security than an aeronaut in the car of a balloon ; it seems scarcely 

 probable that this upward tendency can arise entirely from currents, 

 which, as we observe when feathers are afloat, carry light bodies 

 very irregularly in every direction ; a state of things that would be 

 inconsistent with the economy and safety of the flying spiders. Per- 

 haps the most plausible hypothesis, as to the cause of the ascent of 

 the thread of the aeronautic spider, is that stated by Mr. John Mur- 

 ray ;* he attributes it to electricity, and we cite the following state- 

 ments from his work, as introductory to his conclusion, which we will 

 presently cite, in his own words. 



It appears that the ascent of the aeronautic spider is essential to 

 its existence,! and the great numbers of these wingless insects suffi- 

 ciently account for the abundance of the gossamer, and of the float- 

 ing and fixed threads and tissues, that are so often seen. Sometimes 

 large tracts of ground are covered with them ; two thousand were 

 once obtained in half an hour, and baskets full may be collected, as 

 seen by Mr. White, Sept. 21, 1741 : also, at Bewdley, in Worces- 

 tershire, Sept. 16, 1822, between 11 A.M. and 2 P.M., it was ob- 

 served that the whole atmosphere seemed to be a tissue of cobwebs, 

 falling rapidly ; the temperature was 72^ Fah. Some of the tissues 



Researches in Natural History. Second edition. London: 1830. 



As it i)robably finds much of its food among ihe flying insects of the atmosphere. 



