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£1 
2 ner frightened, though exceedingly near to them, and they 
Ob/ervations on the Garden Spider. 295 
_As the, threads, when they iffue from the body of the 
animal, afcend always obliquely, it appears to me that this 
is produced by the effect of a double impulfe. On the one 
part the infect forces. them out horizontally, and on the 
-other their own. fpecific lightnefs makes them mount verti- 
-eally, from which there refults an oblique direction. This 
fpecific lightnefs is owing, in my opinion, to a kind of ve- 
ficle, fhaped like a very elongated Prince Rupert’s drop, 
which is at the end of the thread at the moment of its 
emiflion. This veficle, the fubftance of which feems to be 
exceedinely thin, is perhaps filled with fome fluid, light, and 
at the fame time vifcous, which poffelfes the double pro- 
perty of making the thread afcend, and of cementing it to 
the bodies which it touches. 
_ Inaword,I have no-doubt that the garden fpider directs 
at pleafure, and towards a determined point, thofe threads 
which it throws out; for I remarked, in the alley above- 
mentioned, that all the webs were vertical and at right an- 
gles to it, which could not be confidered as the effect of 
chance. I hope, therefore, that entomologifts will purfue 
thefe obfervations, in order to difcover, if poffible, by what 
fenfe the fpider judges either of the diftance or the pofition 
of the bodies to which it dire&ts its threads. I obferved 
that the fituation in which it was when it emitted them ‘did 
not allow it to fee the place to which they were direéted. 
a I have fome reafon to doubt that the eyes of fpiders 
_ are actually the organs of vifion. I have often prefented to 
thefe infects dieing bodies, by which they were in no man- 
is “mutt certainly have feen them, had they been endowed with 
+ 
LI 
the faculty of fight. I have even cut off fome of their claws 
re 
ss without, their perceiving the {fciffars; and yet it is well 
hae 
own that, the miftratt of fpiders is fo great, that, as foon 
3s, ‘they have the leaft perception of a flrange object, they 
~~ betake themfelves to flight. On the other hand, if their 
‘web be agitated i in the flighteft manner, as it would be by a 
i fly, 
