The next business is to close the bag.  The machinery works a little differently.  The tip of the belly no longer sways from side to side.  It sinks and touches a point; it retreats, sinks again and touches another point, first here, then there, describing inextricable zigzags.  At the same time, the hind-legs tread the material emitted.  The result is no longer a stuff, but a felt, a blanketing.

Around the satin capsule, which contains the eggs, is the eiderdown destined to keep out the cold.  The youngsters will bide for some time in this soft shelter, to strengthen their joints and prepare for the final exodus.  It does not take long to make.  The spinning-mill suddenly alters the raw material:  it was turning out white silk; it now furnishes reddish-brown silk, finer than the other and issuing in clouds which the hind-legs, those dexterous carders, beat into a sort of froth.  The egg-pocket disappears, drowned in this exquisite wadding.

The balloon-shape is already outlined; the top of the work tapers to a neck.  The Spider, moving up and down, tacking first to one side and then to the other, from the very first spray marks out the graceful form as accurately as though she carried a compass in her abdomen.

Then, once again, with the same suddenness, the material changes.  The white silk reappears, wrought into thread.  This is the moment to weave the outer wrapper.  Because of the thickness of the stuff and the density of its texture, this operation is the longest of the series.

First, a few threads are flung out, hither and thither, to keep the layer of wadding in position.  The Epeira takes special pains with the edge of the neck, where she fashions an indented border, the angles of which, prolonged with cords or lines, form the main support of the building.  The spinnerets never touch this part without giving it, each time, until the end of the work, a certain added solidity, necessary to secure the stability of the balloon.  The suspensory indentations soon outline a crater which needs plugging.  The Spider closes the bag with a padded stopper similar to that with which she sealed the egg-pocket.

When these arrangements are made, the real manufacture of the wrapper begins.  The Spider goes backwards and forwards, turns and turns again.  The spinnerets do not touch the fabric.  With a rhythmical, alternate movement, the hind-legs, the sole implements employed, draw the thread, seize it in their combs and apply it to the work, while the tip of the abdomen sways methodically to and fro.

In this way, the silken fibre is distributed in an even zigzag, of almost geometrical precision and comparable with that of the cotton thread which the machines in our factories roll so neatly into balls.  And this is repeated all over the surface of the work, for the Spider shifts her position a little at every moment.