A SPIDER'S ACTIVITIES. 
97 
directly to it, holds it in her mandibles, sucks the fluids 
from its body and throws away the shell. If, however, 
the pulling indicates a wasp or bee the movements are 
of a different kind. Then the spider shows both 
caution and alertness. If the insect is evidently too 
large to attack, the spider snaps a few threads of her 
web and sets the captive free with as little loss of the 
precious web as possible. If, however, there is a 
chance of victory, the spider spins more threads and 
winds them round and round her victim, until she has 
him so hopelessly entangled that she can safely kill 
and eat him at her leisure. 
The entrance to the spider’s mouth is guarded by a 
pair of mandibles with sharp fangs at their tips. These 
tips have holes near the ends, which lead by tubes to 
a poison-bag in the head. From these fangs the 
poison is squeezed into the body of the fly or other 
insect. 
Nutrition. The spider’s food is always liquid, and 
is pumped up into her stomach in somewhat the same 
way as the butterfly’s honey. In the stomach it 
receives fluids which change it chemically, so that it 
can be used to nourish the body. 
Respiration. Like the insects we have studied, the 
spider has spiracles for breathing, but so active and 
energetic an animal requires more oxygen than this 
arrangement seems able to give, and so it is provided 
with rudimentary lungs or air-sacs. These sacs are 
situated in the anterior part of the abdomen near its 
junction with the cephalothorax, and open by two 
minute holes just behind the last pair of legs. The 
chemistry of breathing is the same in all animals. 
Reproduction. The spider deposits her eggs in a 
cocoon of silk which she makes with great care, 
shaping it with her body as a bird shapes her nest. 
This cocoon, with its eggs, is fastened in a sheltered 
place. The young spiders are hatched quite complete, 
like their mothers, and begin at once to spin each a 
