s the rails, over which the wagons were continually
passing and repassing. Every time they came along a number of ants
were crushed to death. They persevered in crossing for some time, but
at last set to work and tunnelled underneath each rail. One day, when
the wagons were not running, I stopped up the tunnels with stones; but
although great numbers carrying leaves were thus cut off from the
nest, they would not cross the rails, but set to work making fresh
tunnels underneath them. Apparently an order had gone forth, or a
general understanding been come to, that the rails were not to be
crossed.

[Illustration]

SOME WONDERFUL SPIDERS

(FROM A JOURNAL OF RESEARCHES, ETC.)

BY CHARLES DARWIN.

[Illustration]

The number of spiders, in proportion to other insects, is here
compared with England very much larger; perhaps more so than with any
other division of the articulate animals. The variety of species among
the jumping spiders appears almost infinite. The genus, or rather
family of Epeira, is here characterized by many singular forms; some
species have pointed coriaceous shells, others enlarged and spiny
tibiae. Every path in the forest is barricaded with the strong yellow
web of a species belonging to the same division with the Epeira
clavipes of Fabricius, which was formerly said by Sloane to make, in
the West Indies, webs so strong as to catch birds. A small and pretty
kind of spider, with very long forelegs, and which appears to belong
to an undescribed genus, lives as a parasite on almost every one of
these webs. I suppose it is too insignificant to be noticed by the
great Epeira, and is therefore allowed to prey on the minute insects,
which, adhering to the lines, would, otherwise be wasted. When
frightened, this little spider either feigns death by extending its
front legs, or suddenly drops from the web. A large Epeira of the same
division with Epeira tuberculata and conica is extremely common,
especially in dry situations. Its web, which is generally placed among
the great leaves of the common agave, is sometimes strengthened near
the centre by a pair or even four zigzag ribbons, which connect two
adjoining rays. When any large insect, as a grasshopper or wasp, is
caught, the spider by a dexterous movement, makes it revolve very
rapidly, and at the same time emitting a band of threads from its
spinners, soon envelops its prey in a case like the cocoon of a silk
worm. The spider now examines t