's words: "The manner in
which the animal possesses itself of the bubble of air is very
curious, and, as far as I know, has never been exactly described. It
ascends to the surface slowly, assisted by a thread attached to a leaf
or other support below and to the surface of the water. As soon as it
comes near the surface it turns with the extremity of the abdomen
upwards, and exposes a portion of the body to the air for an instant,
then with a jerk it snatches, as it were, a bubble of air, which is
not only attached to the hairs which cover the abdomen, but is held on
by the two hinder legs, which are crossed at an acute angle near their
extremity; this crossing of the legs taking place at the instant the
bubble is seized. The little creature then descends more rapidly and
regains its cell, always by the same route, turns the abdomen within
it, and disengages the bubble." Spiders have strong jaws; at the
bottom of each hooked jaw there is a small sac which contains a
poisonous fluid; this fluid is conveyed by a narrow channel from the
sac along the jaw, and is pressed out at an opening or slit at the tip
of the fang into the wound inflicted on its victim. The feet of
spiders are generally terminated by two or more claws furnished with
teeth; by means of these combs the animal is enabled to manage the
threads of its web with great dexterity and efficiency.

[Illustration: SPIDER'S FANG, MAGNIFIED.]

[Illustration: SPIDER'S FOOT, MAGNIFIED.]

[Illustration]

WALK IX.

JULY.

Let us be off to the fields once more; the sun is very hot, but we can
find refreshing shade under the trees when we are tired. What is this
beautiful little plant with bright scarlet flowers fully expanded? It
is the scarlet pimpernel, or "poor man's weather-glass;" for on rainy
days, and even before the showers are coming, the little plant,
conscious of their approach, closes up its flowers. Other wild
flowers, such as the convolvulus, close before rain. The little
pimpernel, however, is supposed to be the best barometer. There is
another thing about the pimpernel; you will not often see its blossoms
expanded after three o'clock in the afternoon. In other countries,
also, the regular closing of the flowers has been noticed. Dr. Seeman,
who went as naturalist on one of the Arctic Expeditions, noticed the
flowers to close during the long day of an arctic summer. "Although,"
he says, "the sun never sets while it lasts, the plants make no