SNAKK VhWOMS 1 17 



forinciits in snake venom (Inc. rit.). It is highly proliahl ■, iiowever, thit many 

 of tlie thrombi of venom poisoning are not prixhiced by coagiihition of fibrin, but 

 by agpihttination of tlie r(>(i corpusflos, wliich Floxncr'^ has .sliown can cause 

 largo clots in the heart and great vessels, as well as "hyalin" thrombi in the 

 small vessels, lloussay"" states that most snake venoms destroy the cytozyme 

 (which combines with serozyme and calcium to form thrombin), so that the blood 

 becomes incoagulable. The Argentine crotalus and lachesis venoms, however, 

 coagulate even <'it rated blood. 



Nature of Venoms. — The varied effects produced by venoms have 

 been found to be chic to a number of poisonous elements which they 

 contain, and Avhich have been chstinguished and separated from one 

 another by Flexner and Noguchi.^"^ These are hemotoxins [hemoly- 

 sins and hemagglutinins) , leucocytolysins, neurotoxins, and endothel- 

 iotoxins {hemorrhagin) , but it must be taken into consideration that 

 Fausf*^ beheves that the single glucosidal poison which he has found 

 in rattlesnake venom is responsible for all the effects of the venom, 

 except the hemagglutination. [In another place (see "Hemolysis") 

 the nature of the hemolytic agent is discussed.] Venom agglutinin is 

 quite independent of the hemolysin, for it is destroyed by heating to 

 75°-80°, whereas the hemolysin is destroyed only partly at 100°. 

 Agglutinin acts in the absence of serum complement, and therefore 

 is not an amboceptor; it is apparentlj^ more like the toxins in its na- 

 ture. The agglutination of the corpuscles does not interfere with 

 their subsequent hemolysis. Michel states that the agglutinin of cobra 

 venom can be separated from the hemolysin and the toxin by means of 

 ultrafiltration through collodion membranes, as the agglutinin exists 

 in larger molecular aggregates. "^^ ' 



The leucocytotoxins were found by Flexner and Noguchi to be 

 quite distinct from the hemolysins, for after saturating all the hemoly- 

 sin with red corpuscles, the venom still shows its effects on the 

 leucocytes, which effects consist in cessation of motility and disintegra- 

 tion, affecting particularly^ the granular cells. The leucocytotoxin, 

 however, resembles the hemolysin in that it appears to be an ambo- 

 ceptor. Leucocytes are also agglutinated by venom, possibly by the 

 same agglutinin that acts on the red corpuscles. Serum complement 

 is inactivated in vitro by cobra venom through changes in the 

 globulins brought about by the venoms.'*'^ By saturating venom with 

 either red corpuscles or nerve-cells it was found by Flexner and No- 

 guchi that the toxic principle for each is distinct and separate. ^^ 

 Other sorts of cells, however, are able to combine, or at least remove 

 some parts of the toxic elements, but to a much less degree. The 

 neurotoxin, like the hemolysin, resembles an amboceptor, and since 



*^ Univ. of Penn. Med. Bull., 1902 (15), 324. 



"" Prensa Med. Argentina, 1919 (6), 133. 



*' Jour. Exp. Med., 1903 (9), 257; l^niv. Penn. Med. Bull.. 1902 (15), 345. 



••s Arch. Exper. Path. u. Pharm., 1911 (64), 244. 



« Compt. Rend. Soc. Biol.. 1916 (77), 150. 



" Hirschfeld and Klinger, Biochem. Zeit., 1915 (70), 398. 



