222 
WEB-SPIDERS. 
the mother carries the cocoon about with her, either attached to her spinners or 
clasped between her jaws. The young hatch inside the cocoon, and subsequently 
make their way to the outer world through a rupture in its walls. They appear 
in a helpless state, either clinging together in clusters, as in the Argiopidce ; staying 
in the nest, as in the jumping spiders; or clambering 
on to their mother’s back, as in the wolf - spiders. 
During growth the skin is periodically cast, the mem¬ 
brane of the cephalothorax splitting above the base of 
the limbs, and the carapace being raised to make an 
aperture, through which the body with the new skin 
emerges. The young spider is then soft, limp, and at 
the mercy of its enemies, until the integument becomes 
sufficiently hard and resisting to afford firm support 
to the muscles. Consequently, during this time, many species seek shelter in 
silken tubes spun for the purpose. On an average, perhaps, spiders undergo about 
eight or ten moults before reaching maturity, which is attained during the period 
intervening between the last moult and the last but one, so that the males and 
females, which during growth are much alike, emerge from the final casting in a 
fully developed state. In this stage the two sexes are distinguishable, the female 
having the palpi normally constructed, while in the male the terminal segment 
of this appendage carries on its lower surface an organ which in its simplest form 
is somewhat flask-shaped, but is more 
often variously modified and compli¬ 
cated. The male, also, is generally 
rather the smaller of the two, some¬ 
times indeed, as in many tropical 
members of the family Argiopidce, 
being of quite insignificant size in 
comparison with the female. He also 
has longer legs and a thinner abdomen, 
being thus the more graceful and 
active of the two. In the most 
sedentary of all spiders, or those 
belonging to the families Theridiidce 
and Argiopidce, still more striking 
differences often occur, the front part 
of the carapace being sometimes raised into a high pinnacle-like outgrowth. When 
the two sexes are approximately equal in size, the male is comparatively safe from 
his spouse during the period of courtship, but when, as in the Argiopidce, he is much 
the weaker of the two, the female often avails herself of her superiority in size and 
strength to devour her mate. The first uses of the silk-glands seem to be to supply 
material for the construction of the cocoon, and of a tent or tubular retreat for 
the protection of the mother and young, or for the latter when passing through 
the dangers attendant upon the casting of the skin. Such cases are also used for 
the same purpose by many species during the winter months in temperate latitudes, 
and during drought in more tropical climes. It thus appears that, in the first 
female of wolf-spider ( Pardosa amentata) carrying 
HER COCOON. 
Below is shown the arrangement of the eyes when 
seen from above. 
female of Drassus laying 
HER EGGS. 
