180 ARTICULATES: INSECTS. 



unite into one, forming the single line of spider-web 

 which all are so familiar with. As the threads issue 

 from the knobs they are a sticky fluid, which. has 



Ffg. 340. Spider Lycosa. 



been secreted in little bags in the abdomen: but this 

 hardens into silk as soon as it comes to the air. The 

 length of the line which a spider is able to produce is 

 truly wonderful. Dr. Wilder wound nearly two miles 

 of silk, in less than a day, from his celebrated NepJiila 

 plumipes, a spider which he discovered in South Car- 

 olina. The kinds of Spider are very numerous, and 

 most of them spin some sort of a net-like web, in or 

 near which they live, and by means of which they cap- 

 ture insects for food. The House Spider spreads a flat 

 net in the corners of rooms. The Geometric Spider 

 spreads a vertical net, which is made in the most beau- 

 tiful manner, radiating lines running from the centre, 

 like the spokes of a wheel, and these connected by a 

 spiral line, which at a little distance gives the appear- 

 ance of lines arranged in circles from the centre out- 



