406 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1938 



preparing snares for prey. Laymen are but little interested in 

 spiders because their apparent economic value is negligible. The 

 average person is likely to have an active dislike, if any feeling at all, 

 for spiders. This dislike is not based on justifiable fear. The effect 

 of the bite of a spider has long been a question. The Tarantula, a 

 small wolf spider of southern Europe, figured in early legends because 

 of the music and extravagant bacchic display designed to incite the 

 patient to the violent dancing which was thought to be the sole cure 

 for its bite. 



The only other type of spider that has gained a wide and infamous 

 reputation is Latrodectus, a genus of the family Theridiidae. Stories 

 of the deadly nature of the bites of these spiders are current among 

 the peoples of all the regions of the world in which they occur. It is 

 difficult to believe that there is no basis in fact for the similar beliefs 

 that have grown up in such widely separated regions as Europe, 

 America, Madagascar, New Zealand, Algeria, and the West Indies. 

 Arachnologists of the old school were inclined to believe that the 

 stories were based on mistaken evidence. Even today some main- 

 tain that the reports of the venomous qualities are greatly exaggerated. 

 In the case of Latrodectus, incomplete observation gives conflicting 

 evidence. There are authentic reports of bites of this genus of spider 

 being followed by no harmful results. There are equally authentic 

 reports of fatalities, or of more or less serious and disagreeable symp- 

 toms, followed by recovery. 



The divergence of opinion in regard to the effect of the bite has a 

 simple and reasonable explanation. All spiders have poison glands, 

 which open near the tips of the fangs of the chelicerae. The contents 

 of the poison sac are expelled by muscular action, undoubtedly volun- 

 tary on the part of the spider. A "bite," therefore, does not neces- 

 sarily imply the injection of the venom, but might be entirely harm- 

 less. The injection of varying amounts of venom would explain the 

 gradations in the seriousness of the consequences. Nothing but 

 carefully controlled laboratory experiments can give conclusive 

 evidence in a question of this sort. 



The fact that the spider has many common names indicates an 

 enforced recognition. The natives of Madagascar know their two 

 species as "Vancoho" and "Mena-vedi." The New Zealand species is 

 the "Katipo." Latrodectus 13-guttatus of southern Europe is known 

 as the "Malmignatte." The common American species, Latrodectus 

 mactans, was the "Pokomoo" of the Indians, who knew the potency 

 of its venom for making poisoned arrows. Other common names for 

 this spider are the "Black Widow," the "Hourglass," or "Shoebutton" 

 spider 



The Standard Dictionary says that the derivation of Latrodectus is 

 apparently from two Greek words meaning "pay received." Jaeger 



