90 



ZOOLOGY 



FIG. 87. Agalena, the common 

 grass spider. Nat. size. Photo, 

 by W. H. C. P. 



young are borne on the back of 

 the mother. The great size, 

 black color, and hairiness of 

 some of these spiders have given 

 them an apparently unjustified 

 reputation of being very poison- 

 ous. Naturalists who have al- 

 lowed these spiders to bite the 

 hand report that the bite is rarely 

 more poisonous than that of the 

 mosquito. 



(3) Jumping spiders (Salti- 

 gradse *). This family includes 

 many familiar, active species of 



high intelligence. Some of these of grayish color live in 

 houses, and are recognized 

 as members of this family 

 by their half-running, half- 

 jumping gait (Fig. 90). 

 The cocoon is attached to 

 some object and enclosed 

 in a sort of tent, in which 

 the mother also lives to 

 guard the young. 



The economic impor- 

 tance of spider webs is con- 

 siderable. First of all, 

 they are of the greatest 

 importance in capturing 

 many destructive insects, 

 such as flies, mosquitoes, 

 and moths. Another use 



1 saltus, jumping, + gradus. 



o o 



o o 



FIG. 88. Thotnisus, a crab spider. Dia- 

 gram showing arrangement of eyes at 

 bottom of figure. From Emerton. 



