The cocoons of spiders are seldom left exposed and unprotected.  We find them in corners and crevices, concealed in rolled up leaves or under bark.  Very often the cocoon itself is covered over with a sheet of web.  In some families the mother carries it about with her attached to the underside of the abdomen.  In other she carries it in her falces until the young are hatched.  The cocoons of others, as Uloborus, Argyrodes, etc., while hung out in the web are still concealed by deceptive form and color, or by being covered with rubbish.

Cambridge speaks of A. brunnea, whose cocoons “are covered over very soon after they are made and the eggs deposited in them, with a coating of clay, which effectually destroys all their form and beauty.  This coating of clay answers probably two ends:  first, the concealment of the cocoon and its protection from insect enemies; and, secondly, the protection of the eggs from the too powerful rays of the sun, dry clay being (as is well known) one of the best non-conductors of heat.”

The peculiar cocoon of C. bisaccata is described by Emerton as follows:  “Only one specimen of this (bisaccata) was found on a beech tree at New Haven with two cocoons.  These were dark brown, as dark as the bark of the tree and as hard.  Around the middle of each was a circle of irregular points.  One of the cocoons was attached by a strong stem to the bark, and the other was attached in a similar way to the first cocoon.  The spider held on to one of the cocoons.”  In this instance the egg has evidently the same protection as that possessed by the gray, bark-haunting spiders, with the added advantage of hardness.

The habit of distributing the eggs through a number of cocoons made at intervals of several days, is protective.  In this way, although one or two of the cocoons may be pierced by the ichneumon, there is a chance that part of the brood may survive.

INDIRECT PROTECTION.—­The indirectly protected group includes those spiders which are rendered inedible by the possession of sharp spines and chitinous plates, and also those that mimic other specially protected creatures.

The females of the specially protected group are characterized by the following attributes: 

Their inedibility, which they owe to a more or less coriaceous epidermis and an armature of strong sharp spines (Fig. 6).

Their brilliant colors—­glistening black and white, yellow, fiery gold, metallic silver, rose-color, blue, orange and blood-red.

Their habit of hanging always exposed in the centre of the web.

[Illustration:  FIG. 6.—­GASTERACANTHA CREPIDOPHORA (from Cambridge).]

In an interesting discussion of the protective value of color and marking in insects, Poulton says that “the smaller convergent groups of nauseous insects often present us with ideally perfect types of warning patterns and colors—­simple, crude, strongly contrasted—­everything subordinated to the paramount necessity of becoming conspicuous,” the memory of enemies being thus strongly appealed to.