448 
SUPPLEMENT 
it has fixed a great number in this direction ; after this, it 
places more in an opposite line ; and as all these threads are 
gluey, they become cemented one to the other, and soon form 
a tolerably solid web. 
The Epeira diadema, which makes a perpendicular web 
with radii, and the threads of which lead to a common centre, 
proceeds in another fashion. According to the majority of 
authors, it suffers itself to hang to its thread, and the wind 
carries it to a tree different from that to which it was at first 
attached ; it there applies one end of its thread. This done, 
it returns to the middle of this thread, along which it walks, 
where it attaches a second, the extremity of which it fastens to 
some branch near the first, and so on. The opinion of Lister 
is, that the araneides can shoot their threads to a very great 
distance, as the porcupine shoots his quills, with this difference, 
however, that the quills of the porcupine are detached from its 
body, whereas the threads of the araneides remain attached. 
This opinion has been combated. People have been unable 
to conceive that the silk, which hardens in the air, can be 
syringed in this manner, like a fluid. Besides, it has been 
contended, that so weak a thread could not be shot any dis- 
tance without being forced by the resistance of the air to fold 
upon itself, and envelope the body of the animal. Be this, 
however, as it may, M. Latreille has very distinctly observed 
tli e Aranea cancer turning on itself, and darting in all directions, 
in a horizontal line, a thread proceeding from the anus. 
We shall now explain how the Epeira diadema makes its 
web between two branches, or two trees, separated from each 
other by a ditch, or by a stream which it cannot cross. In 
calm weather, placed at the end of some branch, it remains 
firm on its front feet, and with its two hinder feet it draws 
from its nipples a thread, tolerably long, which it suffers to 
float in the air. This thread is pushed by the wind against 
some solid body, where it is quickly cemented by its natural 
