he spider, was
_above_ the other. By putting a spider under the influence of
chloroform, and then carrying the first thread under a pin stuck in a
cork to one part of a spindle, and the second or yellow line over
another pin to a different part of the spindle, I reeled off from the
same spider, at the same time, two distinct bands of silk, of which one
was a deep golden-yellow, the other a bright silver-white; while, if
both threads ran together, there was formed a band of _light yellow_
from the union of the two. Thinking such a difference must subserve some
use in the economy of the insect, I made a more careful examination of
its webs. At first sight these resembled those of most geometrical
spiders, in being broad, rounded, nearly vertical nets; but they were
unusually large, and in their native woods often stretched between trees
and across the paths, so as to be two, three, and even more, feet in
diameter, and in my room at Mt. Pleasant hung like curtains before the
windows. They were of a bright yellow color and very viscid; but now I
noticed that neither the color nor the viscidity pertained to the entire
net, for although the concentric circles constituting the principal part
of the web were _yellow_, and very _elastic_, and studded with little
beads of _gum_, (Fig 3,) yet the diverging lines or _radii_ of the
wheel-shaped structure, with all the guys and stays by which it was
suspended and braced, were _dry_ and _inelastic_, and of a _white_ or
lighter yellow color.

[Illustration: Fig. 3. Silk threads, viscid and dry.]

Now, however, a new mystery presented itself. We will admit that the
spider had the power, not only to vary the _size_ of her lines according
to the number of spinners, or of the minute holes in each spinner, which
were applied to the surface whence the line was to proceed, but also to
make use of either golden or silver silk at will. But how was it that
this yellow silk--which was quite dry and firm, though elastic, as
reeled from the spider, or as spun by her in the formation of her
cocoons--was nevertheless, when used for the concentric circles of the
web, so viscid as to follow the point of a pin, stretching in so doing
many times its length? A satisfactory explanation of this has never yet
been offered, nor can be until the minute anatomy of the spinning organs
is better understood, and the evolution of the silk more carefully
observed at every stage, and under all conditions. I will mer