The history of silk, cotton, linen, wool, and other fibrous ... - Cd3wd.com

SILKEN MATERIAL OP THE SPIDER. 145
The opinion, indeed, is equally improbable with another sug-
gested by Dr. Lister, that the spider can retract her thread
within the abdomen, after it has been emitted*. De Geerf very
justly joins Swammerdam in rejecting both of these fancies,
which, in our own earlier 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 ma-
terial to escape, or stopping it at pleasure, but this is not pro-
jectile.
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 ; and places herself upon
the end of a branch, or some projecting Ijody, and there fastens
her thread ; after which, with her two hind feet, she squeezes
her dugs {spinnerets)^ and presses out one or more threads of
two or three ells in length, which she leaves to float in the air
till it be fixed to some particular placet." Without pretending
to have observed this, Swammerdam says, " I can easily com-
prehend how spiders, without giving themselves any motion,
may, l>y only compressing their spinnerets, force out a tliread,
which being driven by the wind, may serve to waft them from
place to place§." Others, proceeding upon a similar notion,
give a rather different account of the matter. " The spider,"
says Bingley, " fixes one end of a thread to the place where
she stands, and then with her hind paws drairs out several
other threads from the nipples, which, being lengthened out
and driven by the wind to some neighboring tree or other ob-
ject, are b}^ their natural clanmiiness fixed to itil."
Observation gives some plausibility to the latter opinion, as
the spider always actively uses her legs, though not to draw
out the thread, but ascertain whether it has caught ujwn any
object. The notion of her pressing the spinneret with her feet
* Hist. Aniin. Anglae, 4to. t M^moires, vol. vii. p. 189
t Spectacle de la Nature, vol. i. § Book of Nature, pt. i. p. 25.
11 Animal Biography, vol. iii. p. 475, 3d edition.
19