THE CENTIPEDE. 63 



vicious looking spiders. In neither case was there 

 any indication of a poisonous effect. Such is the testi- 

 mony also of almost every other experimenter with 

 spiders. 



Some spiders spin webs. The web is of silk, and 

 comes out as a liquid from numerous tubes which 

 constitute the spinnerets. It hardens upon exposure 

 to the air. There seems little probability of making 

 use of spider web in a commercial way, although the 

 French government is making elaborate experiments 

 in regard to it. Each spider would have to be kept 

 in a cage by itself, for when several are put together, 

 some of them will eat the others until only one is left. 

 This would make spider silk very expensive. 



The webs are sometimes of quite intricate patterns. 

 When an insect flies into one of the webs, the watch- 

 ful spider hurries out and wraps it about with silk, 

 thus completely entangling it, and then proceeds to 

 eat the soft parts of the captive. 



Some small spiders are enabled to travel long dis- 

 tances upon the webs they weave, which are buoyed 

 up and drifted about by the air. 



The jumping spiders luake no webs, but seize 

 their prey by jumping upon it. They are very 

 active. Among nearly all spiders, the female is the 

 larger. 



The eggs of spiders are laid in a mass which, in 

 some species, is surrounded by a covering of silk and 

 either carried around by the spider or fastened to a 

 tree or other support. The metamorphosis is direct. 



THE CENTIPEDE 



{Scolopocryptops. ) 



1. Are there any body divisions? Identify the 

 head distinctly. 



2. Are there any eyes? What kind? 



