ON ARACHNID A. 
451 
tu din ally by blackish bands. Its aperture is hermetically 
sealed by a silken plug. This envelope contains a second, 
the tissue of which is still softer : it is a true down, which 
preserves the eggs from any accident. Almost all the cocoons 
of the arane'ides are equally composed of two kinds of silk, 
the interior of which is finer, and softer to the touch. 
The insects which do not live in society, as soon as their 
eggs are laid, give themselves no further care touching their 
posterity. Many of the arane'ides, on the contrary, guard 
with the utmost vigilance the fruit of their amours ; some even 
carry between their feet their eggs, shut up in the cocoon. 
When the young ones are first disclosed, they attach them- 
selves on the back of their mother. All the eggs are of a 
round form, white, or yellowish white. Those of many species 
exclude fifteen or twenty days after they have been laid ; 
others pass the winter, and do not exclude until spring. Some 
days before the young issues forth from them, the pellicle, 
which is very slender, changes form, and suffers all the parts 
of the insect to appear. 
As soon as the young arane'ides which make webs have left 
the egg, they begin to spin directly. The female lycosse tear 
open the cocoon, which encloses their young, to give them a 
greater facility of coming forth, at the moment in which they 
should quit it. These mount on the back of the mother, who 
carries them along with her ; and when she finds an insect, 
she shares it with them. The arane'ides, in general, exhibit 
a very great attachment to their young. All the young 
arane'ides live, as it were, in society, until the first moulting : 
they then separate, and become mutual enemies. They grow 
very much in their youth, and in augmenting in volume, they 
change their skin. It is believed that they quit it three times 
before they are in a state for reproduction. Their life is more 
or less long. Audebert brought one up, and preserved it for 
several years. 
