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SUPPLEMENT 
aerial web is woven, which is suspended over our heads ; the 
regularity of the numerous concentric circles, and the radii 
which cut them, and give to this web the form of a circular 
net-work. Examine its points of attachment : it is wonderful 
to conceive how the animal which has constructed it has been 
able to fix them, and that too at such considerable distances 
from each other. Our garrets and apartments, long left in a 
state of neglect, serve for an habitation to many species whose 
mode of labour is not the same. Some of them give to their 
web a more compact and thicker tissue, which allows no 
meshes to appear, and which they place in a horizontal situ- 
ation. Another spider, having established its sojourn in cel- 
lars, exhibits a tapestry, whose whiteness rivals that of snow. 
Some form a species of cylinder in a hole between leaves, and 
there remain in ambush. The argyronetes form, in the midst 
of the waters, an oval cocoon, filled with air, carpeted with 
silk, from which proceed threads, in all directions, and 
attached to the plants in the neighbourhood ; there they 
watch their prey, and when the necessity of respiration, or 
other motives, force them to issue from their domicile, they 
envelope their abdomen with a bubble of air, which presents to 
the eyes of the astonished observer the spectacle of a silver 
globe rolling rapidly in the midst of the waves. Some min- 
ing araneides, or those which dig subterraneous galleries, 
know how to close the entrance of their habitation, with a 
door of clay, fixed by means of a sort of hinge, opening at 
the will of the animal, and falling by its own proper force 
and position. 
Endowed with an instinct less surprizing, the araneides 
( inequiteles , Latreille), attach on trees, to the corners of walls, 
in garrets, &c. some threads, the union of which has no deter- 
mined figure, but forms loose and irregular webs. 
These animals remain tranquil at the centre of the snare, or 
in the cell which they have constructed near it. Woe to the 
imprudent insect which should fall into their net! the 
