140 



GENERAL ZOOLOGY 



By spring a comparatively small number of spiders emerge; 

 for they are cannibals and the survivors have lived only 

 because they had brothers and sisters to eat, no other food 

 having been provided for them. By successive molts, with- 

 out marked metamorphosis, they reach their adult size. 



The dark-colored, hairy spiders (Lyco'sa) found under 

 sticks and stones are called wolf spiders. They usually build 



tubular tunnels in the ground, which 

 they line with silk. These do not make 

 a web to capture their prey, but spring 

 upon it as they run about in search of 

 food. The females may often be seen 

 dragging after them the large gray ball 

 which contains, at first, their eggs, and 

 afterwards the young. After a certain 

 time the young leave the silken case, 

 and for some time longer run about over 

 the body of the mother. 



These spiders are often called tarantu- 

 las, but that name should be restricted 

 to the large hairy spiders of the warm 

 parts of the world. The true tarantulas 

 (Fig. 77) can be distinguished from all 

 other spiders by the fact that the ter- 

 minal segment of the chelicerse works vertically instead of 

 horizontally. Tarantulas are universally dreaded in the 

 countries where they grow to be of large size, and they are 

 believed to be very poisonous. The ability of any spider 

 to pierce the human skin depends, of course, on its size and 

 the strength of its jaws ; the effect produced by the bite 

 depends not only on the amount of poison injected into the 

 wound but also on the age and mental and physical condi- 

 tion of the person bitten. Though many stories of death 

 by tarantula bites have been told, most of them are clearly 



Fig. 76. Egg case of 

 garden spider. (Nat- 

 ural size) 



After Wilder 



