It'
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THOUGH this obfervation clearly fliews, that the Spider, thus inhabiting the water, lives
• by means of air, yet there is no reafon for denying it the title of Water-Spider, as feveral
' circumilances demonftrate.
I MUST remark that this Spider, which comes np for air four times in an hour, or oftener,
gave me an opportunity of obferving it for many hours together, by which means I difcovered
that this refrigeration, or refpiration, was not neceifary fo frequently as the Spider pradifed it,
and that it can, as I have good reafon for fuppofmg, continue without it, for feveral days
together.
IT may alfo be proper to remind my readers of the nature of the Aerial-Spiders; and as
from this obfei-vatlon the neceffity of refpiration, as well as the part conducing it, being very
apparent, muft beg permiffion to obferve, that the threads which are emitted, fometimes
from one tubercle, fometimes from another, and fometimes from feveral together, are drawn
out in the manner of mucus from the human noftrils. Confidering likewife the faculty
which this Spider pofleffes, of fliutting or opening any particular tubercle, or, as I think it
may be more properly termed, Spiracle, as alfo the power of receiving and emitting thread
at pleafure, through this or that aperture, and laftly the continuity of the fubftance itfelf;
it follows, that thefe Spiders are fpinners, and poffefs that power in a high degree.
I AM the more perfuaded of this, from the circumftance of their being able to retraft a
recent or juft emitted thread, but not an old or dry one. Could I pretend to the name and
character of an experienced naturalift, perfefled by a long feries of experiments, I might expeft
a greater degree of attention to this theory of mine. At prefent it is fubmitted to the
farther and better judgment of others.
THE tubercles, or fpiracula, are four in number, and while the Spider raifes them for the
purpofe of refrigeration or refpiration, fo as to projeft above the water, they feem larger or
more confpicuous, a little opened or feparated fi'om each other; at other times they are contra6ted
and obfcure. The arms of the male, as appears from the figure, are iliaped like a
gunpowder horn or flaik, with a fmall one in its concavity. Thofe of the female are
cylindric : thofe of both are long and hairy. The holders are largiih, itrong, blackiih, bright,
a little prominent and divaricating, and have thin fcattered Iiairs, and ftrong, browniih, glofly
hooks or claws. I found one male and ten females, which I put into a glafs filled with
water, in hopes of being able to obferve their manner of breeding, or at leaft their battles,
which
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which I imagined not unlikely to happen, confidering the voracity of the animals j hut contrary
to my expeftation, they lived together very quietly for the fpace of eight days, without
any aliment, fo far as I could perceive. I alfo put fome duck-weed (lemna) into the
glafs, as thefe Spiders are fond of taking refuge underneath it. On the 9th and loth days,
the females began to ftretch threads from the lemna to the fides of the glafs, at about a third
of the height from the bottom. On the i ith, they thickened the threads, but in a confufed
manner; the threads which were firft fpun were faftened diagonally, and the Spiders feemed
to amufe themfelves in walking longitudinally upon them. On the 12th day, the male was
feparated from the females, and placed in a glafs by himfelf. On the day following, two of
the females fixed a clofe bag to the edge of the glafs, from which the water was expelled by
the air from the tubercles, and thus a cell was formed, capable of containing the whole
animal. Having done this, and air enough being emitted to drive down the water to the
bottom of the cells, they quietly remained there, the abdomen poffeffing the cell of air, and
the thorax ftill plunged in the water. In a few days, the reft of the females finiihed their
cells in the fame manner. In a lliort time, brimftone-coloured bags of eggs appeared in each
cell, filling about a fourth part of them. They now very rarely quitted their nefts, but often
plunged the thorax and legs fomewhat deeper into the water, whilft the region of the tubercles
was ftill kept in the dry. Four days after, I poured off half the water, and put in freih. On
the 7th of July, feveral young ones fwam out from one of the bags. I opened the other bags,
and found the eggs very fmall, feparate, and round. From the middle of May to July, they
had nothing to eat, and yet they never attacked one another, as the Aerial Spiders are ready
to do upon fuch occafions.
C H A P T E R IX.
OF TWO-EYED-SPIDERS.
AMONGST more than fixty Spiders defcribed in the courfe of this work, there is evidently
a general fimilitude. The Tivo-eyed Spiders, however, are more ftrikingly diftinguiihed from
the proper ones, than the birds of the order Accipitres, are from thofe of the order Gallina.
T Of