how Spiders effect their atrial Excursions. 457 



on the 2nd of October, and inclosed in glass phials with ground 

 stoppers, where they were sutlered to remain till the l6"th of 

 December, an interval of seventy-five days, without either food 

 or moisture ; yet at the expiration of that period, the only alte- 

 rations perceptible in their external condition were a small de- 

 crease in bulk, and a slightly wrinkled appearance, particularly 

 of the abdomen : but their functions were seemingly unim- 

 paired ; for on warm days, or when excited by artificial heat, 

 they were lively in their motions, and to the last continued 

 to produce their threads, which were often destroyed for the 

 purpose of ascertaining whether they would be replaced by 

 others with apparently the same facility as at the time of their 

 capture. 



It is particularly deserving of notice, that these insects, though 

 unable to climb up the smooth perpendicular sides of the phials 

 on their first introduction, soon contrived to traverse the interior 

 of their prisons in every direction . 



In order to illustrate their manner of proceeding on this occa- 

 sion, the case of an individual has been selected for descrip- 

 tion, — the same method, with a few trivial modifications, being 

 pursued by all. Elevating the abdomen, and pressing the spin- 

 ning-apparatus against the side of the phial, this spider emitted 

 from its papilla? a little viscous fiuid, which on exposure to the 

 air hardened into a minute semi-transparent speck ; then moving 

 to a short distance, and drawing out a thread after it, one end of 

 which remained fixed to the spot it had just quitted, it connected 

 this filament with another part of the phial by applying the 

 spinners as before. Several lines being thus produced, the 

 spider speedily raising itself upon them above the bottom of the 

 phial, promoted its undertaking by repeating the process just 

 described ; every step so gained enabling it to carry its opera- 

 tions still higher. 



3 N 2 From 



