152 PHYTOTOXINS AND ZOOTOXINS 



Houssay^* also describes the antiscorpion serum as strictly specific. 

 A large number of naturalists and raconteurs have furnished interest- 

 ing tales of suicide by scorpions, which are more than improbable in 

 the light of our present knowledge concerning natural immunity. 

 Many animals seem to possess more or less immunity to scorpions 

 (Wilson) J especially such wild animals as are much exposed to them. 



Spider Poison 



The poison apparatus of the spiders consists of two long pouches 

 lying in the thorax and extending into the jaws, at the apex of which 

 the poison is discharged. Some of the larger members of the family 

 are very poisonous, e. g., the Malmignatte (Latrodectes tredecim- 

 guttatas), of the vicinity of the lower Volga in southern Russia, is 

 said to have destroyed 70,000 cattle in one year, the bite being fatal 

 in 12 per cent, of all cases, although rarely killing man. Other 

 members of this species in Chili, Madagascar, and other countries 

 are not much less venomous. Kobert^'* has studied the poison of Mal- 

 mignatte and found it distributed throughout the body of the spider, 

 even in the eggs, and resembling in nature the snake venoms. It is 

 destroyed by heating, and seems to be of protein nature; the chief 

 effect is upon the nervous system and heart. "^ 



A number of common spiders investigated by Kobert were ap- 

 parently not poisonous for mammals, except the "cross spider" (Epe- 

 ira diadema) , which has since been thoroughly studied by him and by 

 Sachs.''** Walbum" states that the chief poison of these spiders is 

 found in the ovaries, the salivary poison being much weaker, and the 

 hemolysin is found chiefly in the albumin fraction. Epeiratoxin re- 

 sembles the snake venoms strikingly, according to Sachs, for it con- 

 tains a powerful hemolysin which he calls "arachnolysin," acting very 

 differently with different sorts of blood, and destroyed by heating at 

 70°-72° for forty minutes, and it behaves with lecithin and cholesterol 

 like cobra venom. ^^ By imnmnizing a guinea-pig Sachs succeeded in 

 securing an antitoxin of some strength. The agglutinin is quite dis- 

 tinct from the hemolysin. ^^ Only such blood is hemolyzed as is able 

 to bind the poison in the stroma of the red corpuscles. The discovery 

 of this hemolysin explains Robert's observation of hemoglobin, 

 methemoglobin, etc., in the urine of persons bitten by spiders. Sjiider 

 hemolysins have been studied extensively by Houssay,**" who finds 



'^ "BeitrJige zur Kentnisse der Giftspinnen," Stuttgart. 1901. 



"• In western America and South America is foiind a sj>ider {Latrodectes uiae- 

 lans) the bite of wliich is capable of causing severe spasm of the ah(h)minal musch\s. 

 according Ui At wood (Southern Californ. Pract., \'ols. 10, 12 and 10). Kellogg 

 and (4)lcman (.lour, of Para>itoI., 1915 (1), 107), found extracts of the i)oison 

 glands of this spider to he iiitililv toxic. 



'« Ilofmeister's Heitr.. 1902 (2), 125. 



" Zeit. immunitiit., 1915 (2:5), 02."^. 



'*Pini, 1! I'oliciinico (Se/,. Med.), 1909 (10), 20S. 



'"v. S/.ily. Zeit. Immunitat.. 1910 (5), •^S(). 



«»Comp. Rend. Soc. Biol., 1910 (79), OaS. 



