AFRANIO DO AM ARAL 107 1 



hemorrhages into the internal organs or through the mucous membranes and skin. 

 This is found in the poisoning of the bothropic type. Illstocytolysins in general are 

 prevalent among the solenoglyphous. 



Neurocytolysins are found in large quantity in all the proteroglyphous (Disteiri- 

 dae and Elapidae) and occasionally in a few solenoglyphous (Crolalus terrificus, 

 Agkistrodon spp.). There are three kinds of neurocytolysins: (a) one affecting the 

 bulbar respiratory and circulatory centers, the cranial nerves, and the spinal cord; {b) 

 another the sympathetic nerves of the salivary, lacrimal, and intestinal glands and 

 of the nasal mucosa; (c) and another the neuro-motor apparatus of the diaphragm 

 and the skeletal muscles. It is probable that further work will discover or distinguish 

 other neurolysins. 



Chromatolysin acts on the chromatin of the nerve cell nuclei, and its slow action 

 seems to be responsible both for the relapse or recurrence of symptoms and delayed 

 death, which may be observed in the poisoning by Bungarus candidus, Crotalus terri- 

 ficus, etc. 



Antibactericidin prevents the tropism of the leukocytes and other cells having 

 bacteriolytic power, and thus it helps the development of secondary infections. This 

 antibactericidal action of the venoms, discovered by Welch and Ewing, was' inter- 

 preted by Flexner and Noguchi^ as a fixation or inactivation of the bacteriolytic com- 

 plement, this fixation being brought about either by the venom amboceptor, accord- 

 ing to Noc,2 or by the venom proteolytic ferment, according to Noguchi.^ 



Precipitinogen is found in large quantity especially in the venom of Bothrops spp. 

 It should be noted that Lamb,^ and Calmette and Massol,^ having found that venoms 

 could bring about precipitins in the sera of immune animals, developed a method 

 for antivenin titration based on the precipitin test. 



Hemagglutinin is sometimes found in venoms as, for instance, in those of North 

 American species of Crotalus. It can be distinguished from the hemocy tolysins in that 

 it is destroyed by heating at 75° C. 



Thrombinogen and anticytozyme, respectively, cause blood coagulation and anti- 

 coagulation in the animals bitten by snakes. As a rule, all the proteroglyphous 

 venoms are anticytozymic (anti-coagulant) and the solenoglyphous are thrombino- 

 genic (coagulant). Among the latter, however, those of Daboiarussellii, Trimeresurus 

 flavoriridis, Crotalus atrox, and C. adamanteus are anti-coagulant. Houssay and Sor- 

 delli/ separately or with Negrette,* who carried out an exhaustive study regarding 

 this point, found that any venom can destroy directly the cytozyme and so inhibit 

 blood coagulation unless it possesses thrombinogenic activity. 



Lecithinase is one of the most important antigenic substances because it may be 



' Welch, W., and Ewing, C: Tr. ist Pan- Am. Cong., i, 354. 1893. 



2 Flexner, S., and Noguchi, H.: /. E.xper. Med., 6, 277. 1902. 



3 Noc, F.: Ann. de I'Inst. Pasteur, 19, 209. 1905. 

 ■'Noguchi, H.: Snake Venoms, etc., p. 218. 1909. 

 5 Lamb, G.: Lancet, 11, 431. 1902. 



* Calmette, A., and Massol, L.: Ann. de I'Inst. Pasteur, 23, 155. 1909, 



'Houssay, B., and Sordelli, A.: Arch. Inst, de physiol., is, 378. 1920. 



^Houssay, B., Sordelli, A., and Negrette, J.: Rev. hist. Bad. B.A., i, 52 pp. 1918. 



