ORDER I. PULMONARIA.— SPIDERS. 263 
tables. Those which subsist upon other animals often increase in a very 
great degree. In some species two of the legs are not developed before a 
change of skin, and in general it is not until after the fourth or fifth moult- 
ing that these animals become fitted for reproduction.” 
ORDER I. OF ARACHNIDA. PULMONARIA. 
This order comprises those species which have pulmonary sacs, a heart 
with distinct vessels, a system of circulation, and six or eight eyes. 
ARANEA. — The Spiders. There are no creatures more common than 
these curious beings, and few that are not looked upon with more favor and 
less disgust. Every morning the housewife has to clean with brush or 
broom numerous corners and by-places of the “ filthy cobwebs,” placed there 
the previous night by these indefatigable workers. There is no place secure 
from their intrusion, no part of a human dwelling where they do not at 
times pursue their wonderful labors. The spider has eyes like those of a 
cat, and sees in the night as well as in the day, and while we are sleeping, 
may be constructing its marvellous palace on the very ceiling of our parlor. 
The white, silky masses seen floating in the air in spring and autumn 
mornings are evidences of its nocturnal industry. 
It is probable that many of the spiders, not having a suflicient supply of 
silk, merely emit single threads—such, for instance, as those made by 
young Lycosw, which are to be seen in great abundance, crossing from 
ridge to ridge, in cultivated lands, when they reflect the sun’s rays. When 
chemically analyzed, they are found to exhibit precisely the same charac- 
ters as the silk of spiders, and are, therefore, not formed in the air, as has 
been conjectured by Lamarck. Gloves and stockings have been made of 
spiders’ silk; but these attempts, not being capable of a general application, 
and being subject to great difficulties, are more curious than useful. The 
material is, however, far more important for the spiders themselves. It is 
by its means that the sedentary species, or those which do not chase after 
their prey, construct their webs of a more or less firm texture, capable, in 
some exotic species, of holding small birds, and of which the forms and 
positions vary according to the habits peculiar to each species, and which are 
so many snares in which the insects which serve them for food are captured. 
Searcely is one caught by the hooks of the tarsi, than the spider, sometimes 
placed in the centre of its web, or in a cell near one of its angles, darts 
forth, approaches the insect, uses all its efforts to wound the captive with its 
murderous darts, and to discharge into the wound an active poison. When 
it opposes too strong a resistance, and a struggle may be dangerous to the 
