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

SILKEN MATERIAL OF THE SPIDER. 141
In the figure the threads are, of course, greatly magnified, so
that, for the small space represented, the lines are shown as
parallel. The threadlcts. or filaments as they come from the
papillae, are too fine to be counted with any degree of accuracy,
but it is evident that very many are sent forth from each of the
larger papillse. This fact tends to explain the power possessed
by the spider of producing threads having different degrees of
tenuity. By applying more or less of these papillae against the
place whence it begins its web, the spider joins into one thread
the almost imperceptible individual filaments which it draws
from its body ; the size of this thread being dependent on the
nvnnber of nipples employed, and regulated by that instinct
which teaches the creature to make choice of the degree of
exility most appropriate to the work wherein it is about to
engage.
Reaumur relates that he has often counted as many as seventy
or eighty fibres through a microscope, and perceived that there
were yet infinitely more than he could reckon ; so that he be-
lieved himself to be far within the limit of truth in computing
that the tip of each of the five papillae furnished 1000 separate
fibres : thus supposing that one slender filament of a spider's
web is made up of 5000 fibres !
Leeuwenhoeck, in one of his extraordinary microscopical ob-
servations on a young spider, not bigger than a grain of sand,
upon enumerating the threadlets in one of its threads, calcula-
ted that it would require yb?