734 PATHOGENIC MICROORGANISMS 



directly into the nerves and the central nervous system in active 

 cases. 



Tetanolysin. Tetanus bouillon contains, besides the "tetano- 

 spasmin ' ' described x above which produces the familiar symptoms of 

 the disease, another substance discovered by Ehrlich 30 and named 

 by him "tetanolysin. " Tetanolysin has the power of causing liemol- 

 ysis of the red blood corpuscles of various animals, and is an entire ly 

 separate substance from tetanospasmin. It may be removed from 

 toxic broth by admixture of red blood cells, is more thermolabile 

 than the tetanospasmin, and gives rise to an antihemolysin when 

 injected into animals. 



Pathogenicity. The comparative infrequency of tetanus infection 

 is in marked contrast to the wide distribution of the bacilli in nature. 

 Introduced into the animal body as spores, and free- from toxin, 

 they may often fail to incite disease, easily falling prey to phagocy- 

 tosis and other protective agencies before the vegetative forms 

 develop and toxin is formed. The protective importance of phagocy- 

 tosis was demonstrated by Vaillard and Rouget, 31 who introduced 

 tetanus spores inclosed in paper sacs into the animal body. By the 

 paper capsules the spores were protected from the leucocytes, not 

 from the body fluids. Nevertheless, tetanus developed in the animals. 

 The nature of the wound and the simultaneous presence of other 

 microorganisms seem to be important factors in determining whether 

 or not the tetanus bacilli shall be enabled to proliferate. Deep, 

 lacerated wounds, in which there has been considerable tissue de- 

 struction, and in which chips of glass, wood splinters, or grains of 

 dirt have become embedded, are particularly favorable for the 

 development of these germs. The injuries of compound fractures 

 and of gunshot wounds are especially liable to supply these condi- 

 tions, and the presence in such wounds of the common pus cocci, 

 or of other more harmless parasites, may aid materially in furnishing 

 an environment suitable for the growth of the tetanus bacilli. Apart 

 from its occurrence following trauma, tetanus has been not infre- 

 quently observed after childbirth, 32 and isolated cases have been 

 reported in which it has followed diphtheria and ulcerative lesions 

 of the throat. 33 



30 Ehrlich, Berlin, kl. Woch., 1898. 



31 Vaillard et Rouget, Ann. de 1'inst. Pasteur, 1892. 



32 Baginsky, Deut. med. Woch., 1893, 



, Wien. med. Woch., 1895. 



