f silk covers both
egg mass and fluff, holding it flat against a wall or the trunk of a
tree. In some of the higher spiders, notably our bank spiders, the
silken covering becomes an effective cocoon, spherical in shape, with
a little opening at the top like the neck of a small bottle. The egg
cocoon is woven in a mass of tangled silk between the branches of some
tough weed which will be sure to outlast the winter. Into the egg
cocoon the spider may place one thousand or more eggs. Having thus
provided her children with a snug winter home, the spider dies. When
spring comes with the warm rays of the sun, the eggs hatch and the
cocoon becomes a creeping mass of minute spiders. At the time these
spiders appear there is nothing for them to eat. The obvious way out
of this difficulty is taken. At once there begins a progressive party.
Spider fights with spider, and the prize in each conflict is the body
of the victim, which is promptly eaten. The winners in the first round
pair off again, and a little later, as hunger drives them, another set
of combats comes on, resulting in another halving of the number of
spiders in the cocoon. This process continues until not more than
one-tenth of the original number of spiders remains. By this time they
have gained sufficient strength of leg and jaw, and sufficient
dexterity in the use of both, to make it safe for them to venture out
and try their fortunes among the accidents of a strenuous world. There
can be little doubt after this long process has worked its final
results which tenth remains. Chance plays but small part in this
game. It is the fittest that survive. When this procedure goes on
generation after generation, the result must necessarily be that the
spiders grow fitter and fitter for their work. This method is hard on
the little spider, but it makes good spiders.

Most insects die before their eggs hatch; accordingly they can pay no
attention to their own children. Whatever arrangements are provided
for the safety and strength of these offspring must be provided before
they appear. About the only care the majority of insects take in this
direction is to see that the eggs are placed where the young shall
find food as soon as they emerge. Insects' eggs are very small, and as
a consequence the creatures which emerge from them are likewise
exceedingly minute. As a result they cannot be expected to hunt far
for their food. Different insects use different devices by which to
o