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Though this obfervatlon clearly ihews, 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 
circumftances demonftrate. 
I MUST remark that this Spider, which comes up 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 neceffary fo frequently as the Spider pradtifed 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 obfervation 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 pofieffes, of fhutting 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 poflefs that power in a high degree. 
I AM the more perfuaded of this, from the circumftance of their being able to retra6l a 
recent or juft emitted thread, but not an old or dry one. Could I pretend to the name and 
chara6ler of an experienced naturalift, perfe6led by a long feries of experiments, I might ex- 
pe6t 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 proje6l above the water, they feem larger or 
more confpicuous, a little opened or feparated from each other j at other times they are con- 
tracted and obfcure. The arms of the male, as appears from the figure, are fhaped like a 
gunpowder horn or flafk, with a fmall one in its concavity. Thofe of the female are 
cylindric : thofe of both are long and hairy. The holders are largifh, ftrong, blackifli, bright, 
a little prominent and divaricating, and have thin fcattered hairs, and ftrong, brownifh, glofty 
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 
