_ NATURAL HISTORY. 399 
Spider lies in ambuth behind the net, and patiently waits for its enemy, 
who is not aware of it. : 
Spiders have five tubercles or nipples, at the extremity of the belly, 
whofe aperture they can open and fhut, enlarge, or contract, juft as 
they pleafe. It is through thefe apertures that they {pin the gluey fub- 
Rance with which their bellies are full. In proportion as the fpider 
lets this glue pafs through one of the apertures, the head grows longer, 
as the recedes from the place to which the had fixed the end. When 
fhe contraéts the apertures of the nipples, the fpinning ceafes, and fhe 
remains hanging thereto. She afterwards makes ufe of the thread to 
re-afcend by the help of her claws, much in the fame manner, as fome 
men will fwarm up a rope. However this is not all the ufe which fhe 
makes of this thread. j 
When a houfe Spider is to begin her web, fhe firlt ehufes a place 
where there is a cavity, fach as the corner of a room, that fhe may 
have a clear paflage to pafs freely on each fide, and to make her efcape 
Sf there be occafion. She throws upon the walla fmall drop of this 
glue or gum, and lets fome more pafs through a fmall aperture, and- 
the thread lengthens as fhe draws back, and till fhe has got to the other 
fide, where fhe would fix her web; than fhe lets another drop fall, by 
which the fixes it to the place; thus fhe pafles and repafies, till fhe has 
made it as large and as ftrong, as was firft defigned: thofe that 
have feen them at work, affirm, fhe makes more threads than one at 
the fame time, that fhe may finifh her net the fooner. However it is © 
obfervable, that the firft row of threads, which may be called the 
warp, lye all parallel to each other ; after which fhe crofles them with 
another fet, which may be named the woof, and by a particular art 
that fhe has, fhe faftens them to each other, which perhaps is entirely 
owing to the gluey fubftance fhe makes ufe of. = . 
A Spider feems to know very well, that if fhe appeared epenly, or 
in fight, fhe would mifs of her prey ; and therefore the weaves a {mall 
cell for herfelf, where fhe lies hid, and keeps upon the watch; there 
are two paflages, out of it, the one above, and the other below, that 
fhe may walk out which way fhe pleafes, to vifit her work, and keep 
every thing clean ; for fhe takes away from time to time, the duft that © 
is got upon it, or rather dhakes it off, by giving it a ftroke with her 
paw, which if fhe did not do, it would foon be over-loaded and con- 
fequently the fabrick would be deftroyed, — cs 
‘There are generally a fort of threads, that proceed like rays from 
the center, where fhe is hid, and where fhe ftands centinel 5 fo that fhe 
can readily preceive when any part of the threads are touched, when 
the game is at hand, upon which fhe immediately falls upon it. Ano- 
ther advantage fhe receives from the mechanifm of her cell, is to have — 
a retreat, where fhe may devour her prey in fafety, and conceal their 
carcaffes, that they may no prevent others from falling into the fame 
fhare. 
The magazine of the gum or glue, does not always laft, for when . 
the fpider grows old, it is entirely exhaufted; and then to get her li- 
ving, fhe goes to the web of a young one, who either out of kindnefs, 
or fear, gives place, and weaves herfelf another. é 
The labour of the garden Spider is quite different from the former, and > 
Yet is not performed with lefs art. Many people believe that a 
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