ON ARACHNIDA. 
481 
the precaution of closing the aperture exactly, and it is pro- 
bable that many other species are similarly prudent. 
The lycosae, especially such as frequent the neighbour- 
hood of aquatic places, begin to be found from the earliest 
fine days of spring. Coupling takes place, according to the 
species and the temperature of the weather, from the month 
of May to, the middle of July. The eggs are free, usually 
spherical, and their number varies according to the species, 
being sometimes twenty, seventy, eighty, and even one hun- 
dred and eighty. They are enclosed in a sac or cocoon, 
sometimes globular, sometimes flatted, circular, and formed by 
two caps united at their edges. It is membranaceous, and 
composed of a compact silk. Clerk has observed some 
which were whitish above, and blackish underneath. The 
cocoon of the Lycosa littoralis , one of those whose figure is 
lenticular, is grey externally, with a white circle, and formed 
of a less compact silk ; its interior parietes are whitish ; the egg- 
sac isalwavs attached to the hinder part of the female by means 
of a small pellet, or silken tie, issuing from the spinnerets ; she 
applies the threads over its surface, causing to act upon it 
with rapidity, the nipples, which are the conduits of the silk. 
If we detach this sac, we unwind, at the same time, a thread 
of silk which issues from the spinneret. Lister has even 
maintained that the animal can withdraw this sac into the 
interior of its spinnerets, which Degeer conceives to be im- 
possible. The female always carries this precious deposit 
along with her, and in spite of her burthen, runs with celerity. 
If she is separated from it, she testifies her uneasiness by 
running to and fro on all sides, and as soon as she has found 
it, she seizes and runs off with it. Clerk tells us, with re- 
spect to the species which he names Amentatus , that when 
she has recovered her cocoon, she carries it at first, putting it 
under the belly, and approached a little to one side of the 
VOL. XIIT. I i 
