Other Venomous Spiders 



19 



and though Kobert's results seem conclusive, the spider is little to 

 be feared. 



Phidippus audax {P. tripunctatus) is one of our largest Attids, 

 or jimiping spiders. The late Dr. 0. Lugger describes a case of severe 

 poisoning from the bite of this spider and though details are lacking, 

 it is quite possible that this and other large species of the same group, 

 which stalk their prey, may possess a more active poison than that of 

 web-buUding species. 



Summary — It is clearly established that our common spiders are 

 not to be feared and that the stories regarding their virulence are 



almost wholly without founda- 

 tion. On the other hand, the 

 chances of secondary infection 

 from the bites of some of the 

 more powerful species are not 

 to be ignored. 



Probably all species possess 

 a toxin secreted by the poison 

 gland, virulent for insects and 

 other normal prey of the 

 spiders, but with little or no 

 effect on man. 



There are a very few species, 

 notably of the genus Latrodectus, 

 and possibly including the Euro- 

 pean Chiracanthium nutrix and 

 Epeira diadema, which possess, 

 in addition, a toxalbvimen 

 derived from the general body 

 tissue, which is of great virulence 

 and may even cause death in man and the higher animals. 

 THE PEDIPALPIDA OR WHIP-SCORPIONS 



The tailed whip-scorpions, belonging to the family Thelyphonidce, 

 are represented in the United States by the giant whip-scorpion 

 Mastigopr actus giganteus (fig. 10), which is common in Florida, Texas 

 and some other parts of the South. In Florida, it is locally known as 

 the "grampus" or "mule-killer" and is very greatly feared. There is 

 no evidence that these fears have any foundation, and Dr. Marx 

 states that there is neither a poison gland nor a pore in the claw of the 

 chelicera. 



10. 



A whip-scorpion (Mastigoproctus giganteus). 

 Half natural size. After Comstock. 



