SPIDERS. 343 



lour; and running to the top of the page, and 

 shooting out a iveb, took its departure from thence. 

 But what I most wondered at was, that it went off 

 with considerable velocity in a place where no air 

 was stirring; and I am sure that I did not assist it 

 with my breath."* 



Having so often witnessed the thread set afloat 

 in the air by spiders, we can readily conceive the 

 way in which those eminent naturalists were led 

 to suppose it to be ejected by some animal force 

 acting like a syringe ; but as the statement can be 

 completely disproved by experiment, we shall only at 

 present ask, in the words of Swammerdam — " how it 

 can be possible that a thread so fine and slender 

 should be shot out with force enough to divide and 

 pass through the air? — is it not rather probable that 

 the air would stop its progress, and so entangle it 

 and fit it to perplex the spider's operations?"! The 

 opinion, indeed, is equally improbable with another, 

 suggested by Dr Lister, that the spider can retract 

 her thread within the abdomen, after it has been 

 emitted, J De Geer§ very justly joins Swammer- 

 dam in rejecting both of these fancies, which, in our 

 own earher observations upon spiders, certainly 

 struck us as plausible and true. There can be no 

 doubt, indeed, that the animal has a voluntary power 

 of permitting the material to escape, or stopping it 

 at pleasure, but this power is not projectile. 



3. " There are many people," says the Abbe de la 

 Pluche, " who believe that the spider flies when they see 

 her pass from branch to branch, and even from one 

 high tree to another; but she transports herself in this 

 manner: she places herself upon the end of a branch, 



* Nat. Hist, of Selboine, vol. i. p. 327. 

 t Book of Nature, part i. p. 25. 

 t Hist. Anim. Anglige, 4to. 

 i Memoires, vol. vii. p. 189. 



