298 



KNOWLEDGE & SCIENTIFIC NEWS. 



[Decembkr, 1905. 



The Venom of Spiders. 



Bv C. AiNswoKTii Mitchell, B.A. (Oxon.), l-M.C. 



Spiders have gained an evil and Irequently undeserved 

 reputation as venomous enemies of man, and certain 

 species are still regarded Ijy the natives in some parts 

 ot Africa with as much horror as poisonous snakes. 



We find numerous references in ancient and media;- 

 val writers, i.^., in .Vristotle's Natural History, to tlie 

 deadly effects caused by the bite of spiders, and the 

 facts eventually became so exaggerated :md distorted, 

 that m;my writers in the last century went lo the other 

 extreme and ridiculed the idea of any spider producing 

 injurious results in m;m. 



It is only within the last two or three years that the 

 question has been investigated by scientific methods, 

 and that we have been able to form an opinion as to 

 what amount of truth there was in the old conflicting 

 accounts that have come down to us. 



Leeuwenhoek appears to have been the tirst to 

 give an exact description of the poison fangs of the 

 spider, and his account, published in the Transactions 

 of the Roval S(x:iety for 1 70J (\'ol XXll.. p. 867), 

 opens in the fi>llowing quaint terms : — " I have often 

 heard speak of the Sting of a Spider ;md that with the 

 same he is able to kill a Toad, but having^ never learned 

 whereabout this Sting grew, I fancied it in the Tail 

 as it happens in most l'"lying In.sects." 



He then goes on to descrilje how a frog bitten by a 

 spider died within an hour, whereas a second frog 

 bitten by another spider was not affected in tlie 

 slightest degree. In explanation of this, he suggests : 

 " Now 'tis possible thai the .Stingnng of Spiders in hot- 

 ter Countries may be more pernicii>us than in our 

 Climate ; 'tis also possible ihat this Spider might have 

 spent his I'oyson lately by wounding another Spider 

 or any other Creature." Professor Robert's investi- 

 gations (infra), doubtless supply the true explanation 

 of the difference, which was probably that the spiders 

 belonged to different species. 



In a later volume of the Transactions (17:26;, there is 

 a letter fri>m a Dr. Uobie in New England, giving an 

 account of the serious illness of a man who had been 

 bitten in the leg by a small, bhick spider, but was bet- 

 ter after .14 hours. 



All llie early Italian scientific writers contain ac- 

 counts of cases that had come under their observa- 

 tion. Dr. Silvio Boccone {Miistn di Fisica, Kigj) 

 descril>cs numerous instances where illness had l)ecn 

 caused through the bite of the malmignatte in Corsica. 

 I-'ontana, writing in 1781 on viper poison, mentions 

 that the bite of a certain kind of spider might be fatal; 

 and Dr. Luigi Toti gives a full description of the 

 symptrjms f>f 17 cases that he had himself altended 

 prior to 1794. (Jf these 15 recovered after a few days, 

 one was only saved with difficulty, and one died. 'Hie 

 effects are de.scribed as being exactly similar to those 

 caused by tltc bite of a \iper. He himself was bitten 

 by four of the little m.ilmigmilles, which had just been 

 hatched. There was some inflammation in the \icinily 

 of the bites but no general symptoms. 



Cauro (18,^.^), confirmed Toti's statement as to the 

 cfferls f>f the bile of the malmignatte resembling those 

 pro<lurefl by viper venom, lie st.iird thai the natives 

 of Corsica used a .secret remedy, whii-h he found lo 

 consist of a mixture of opium and camphor, and to be 

 very cfTective. 



The spider to which all these Italian writers refer is 

 the Liitlirodectes ircdaimgiiltatus, popularly known :is 

 the malmignatte. It is about a third of an inch in size, 

 and is characterised by the red spots on its Ijl.ick body. 

 .Vnother liuropean spider belonging to the same family 

 is the Lathrodcctes conglobatm, which is found in Greece. 

 1 1 is smaller than the malmignatte and has white spots 

 instead of red. The Russian species (/-. ercbits), known 

 as the kara-kurte {black wolf), is common in South 

 Russia and Turkestan, where it is a great object of 

 dread. It is jet black, and without any spots. 



Species of spiders lx;longing lo the same family are 

 also found in .-Vmerica (/,. nitii/tins), and in Australia 

 (Z. icclw. " Ktiti/in," and L. Ihiscllii), all of which arc 

 reported to produce symptoms similar to those tvuised 

 by the bile of the Kuropean and Asiiitic species. Both 

 the .Australian species have red spots on a black 

 ground. 



.\ccording to X'inson (Araiietdcs da lies dc la Reunion 

 el Madagascar, 1863), the natives of Madagascar are in 

 deadly terror of Latlirodectcs mcnavodi, which re- 

 sembles the Italian malmignatte in size and appear- 

 ance, but have not the slightest fear of an allied black 

 species. Tliis is cited by Dr. Laboulbene {Diet, des 

 Sciiinfs Medicates) as a proof of the great exagi^era- 

 tion of the effects of the malmignalte Ijilc, and ho at- 

 tributes the fear of the natives solely lo ilic more 

 ferocious aspect of L. mcnavodi. The answer to this 

 contention is supplied bv Dr. Koberts results. 



W'alckenau, in 1837, made some of the largest 

 spilers lo lie found near Paris bile him, and never ex- 

 perienced the slightest ill effects. Similar experiments 

 were made alx)ul the same time by Duges in the South 

 of I'rance. but the most serious result was a slight 

 inf!ammati()n. 



Blackwall, the great authority on British spiders, 

 published the results of his experiments in the Trans- 

 aeliniis oj I lie Linncan Society for 1855 (\'ol. XXI.. p. 31). 

 He found that no ill effects were produced up<in himself 

 by the bite of various spiders, including the garden 

 sjjider (Araiiea diadeniata), and that e\en insects were 

 not affected by the venom injected by the fangs of the 

 spiders. He asserted that " the serious and sometimes 

 fatal consequences which have been attributed to the 

 bile of the malmignalte must he regarded as jimusing 

 fictions in the nalunil history of the Araneidca." 



The l'"rench naturalist, Dufour (1864), also came to 

 the conclusifOT that tin- danger of ihe bite of the spider 

 was to a large extent imaginary. 



ITie question re.maineil in this st;ile of uncertainty 

 ui.til, in 1901, Dr. Robert Robert published an ex- 

 cellent monograph dealing will) the whole subject. He 

 obtained recent data f>f cases of bites, and did an im- 

 mense amount of experimjntal work with spiders of 

 different species, notably the Russian kara-kurte 

 (L. erebus). Detailed reports were sent lo him of 22 

 cases admitted to Ihe hospit.ils in the Chersonese dur- 

 ing 1888. In each instance the bite had fell like m bee 

 sting, and there was usually no swelling around the 

 place, but sf>on violent pains were felt in the limbs, and 

 this W'.-Ls succeetled by difficulty in breathing and cold 

 perspirali(4is, both the heart and central nervous 

 system usu.-illy being affected. Recovery was generally 

 complete after five days. 



Dr. Robert made extracts from Ihe crushed fresh or 

 dried Ixxlies of these spiders, by means of a dilute solu- 

 tion of salt, and thus obtained solutions that were ex- 

 tri-melv poisonous, prfwlucing .'ill the symptoms .atlri- 

 buted to Ihe bites. 



The poison was not cr)nfined lo the glrinds, for ox- 



