VENOMS IN THE ANIMAL SEIUES 



275 



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animals upon which spiders feed. In man and large mammals 

 their bite produces sensations of pain accompanied by swelling 

 and muscular contractions as though caused by localised tetanus. 



The venom of certain species of spiders 

 sometimes causes very serious and even 

 fatal results. Latrodectus malmignattus 

 (the malmignatte of the South of France 

 and Italy), and especially Latrodectus 

 mactans, of Chile (fig. 96), are greatly 

 dreaded.^ The area of distribution of the 

 latter includes the whole of Tropical and 

 Sub-tropical America. It is said that it 

 frequently causes the death of milch cows, 

 and that in man its bite produces tetanic 

 effects, which last for several days, but 

 are in most cases amenable to treatment. 



Another dangerous spider is the Katipo 

 (Latrodectus scelio), of New Zealand. 

 This creature is confined to the sea-shore, 

 and the natives are often bitten when 

 collecting shell-fish or sea-weed. The 

 Maoris are so much afraid of the bite of 

 the Katipo that, when one of them has 

 been bitten in his hut, and the animal 

 cannot be found, they do not hesitate to 

 burn the dwelling to the ground. More- 

 over, they are convinced that the death of 

 the spider is absolutely necessary for the recovery of the patient.- 



Fig. 96. — Lactrodectus 

 mactans (formidabilis olim). 



1, Female, twice natural size ; 

 la, its eyes, greatly enlarged. 



•"El Latrodectus formidabilis de Chile," by Frederico Puga-Borne, Santiago, 

 1892 ; and " Biologia Centrali- Americana," Arachnida, vol. ii., pi. 35. 



-Blaekwell, "Experiments and Observations on the Poison of Araneida," 

 Transactions of the Linnean Society of London, 1855, p. 31. See also "Insect 

 Life" (U.S. Department of Agriculture, 1889), vol, i., parts 7, 8, 9 and 10, 

 and vol. ii., part 5. 



