The Structure and Habits of Spiders. 113 



species are found adult at all seasons, and may 

 live several years. 



After spiders have passed their second moult, 

 they usually live in the same places, and follow 

 the same habits, as the adults. 



The running spiders live usually on the 

 ground, often near water, but some kinds in the 

 hottest and dryest places. A few species live 

 near water, and are accustomed to run about 

 on its surface, without becoming wet. The 

 Theridiidce almost all live in the shade, and 

 always upside down in their webs. Some 

 species live always in caves ; and one in 

 the deepest part of the Mammoth Cave has no 

 eyes. Some spiders live only on high moun- 

 tains, never appearing below the tree line. 

 Some species seem to prefer certain kinds of 

 plants. The horizontal branches of spruces, 

 for instance, are particularly convenient for the 

 webs of some species of Theridion. The 

 water-spider, that builds its nest and lives on 

 water-plants, has been already mentioned, and 

 also the Argyrodes, that makes its home in 

 the webs of other spiders. During winter 

 immense numbers of spiders that have spent 



