Page:The Life of the Spider.djvu/273

 shocks, is never strong enough, especially as it is exposed to the additional burden of little bits of plaster loosened from the wall. The owner is constantly working at it; she adds a new layer nightly.

Every time that she issues from her tubular retreat or returns to it, she fixes the thread that hangs behind her upon the road covered. As evidence of this work, we have the direction of the surface-lines, all of which, whether straight or winding, according to the fancies that guide the Spider's path, converge upon the entrance of the tube. Each step taken, beyond a doubt, adds a filament to the web.

We have here the story of the Processionary of the Pine, whose habits I have related elsewhere. When the caterpillars leave the silk pouch, to go and browse at night, and also when they enter it again, they never fail to spin a little on the surface of their nest. Each expedition adds to the thickness of the wall.

When moving this way or that upon the purse which I have split from top to bottom with my scissors, the Processionaries upholster