142 Edwin O. Jordan 



This experiment gives no support to Mavrojannis' criterion of 

 differentiation. 



The only conclusion that can be drawn from all my observations 

 on this matter is that no fundamental distinction between the different 

 bacterial gelatinases exists in the sense alleged by Mavrojannis. 

 Young gelatin cultures and those liquefied by feeble strains solidify 

 when subjected to the action of formalin; the same is true of some 

 cultures grown at 20° as compared with those of the same species 

 grown at 37°. On the other hand, all the old cultures of vigorously 

 liquefying strains, of whatever species, are not hardened by formalin 

 action. In other words, the difference observed is simply one of degree 

 and not of kind.^ 



RELATION BETWEEN BACTERIAL GELATINASES AND BACTERIAL 



HEMOLYSINS. 



The question has been raised recently as to whether the hemolytic 

 action displayed by certain bacterial filtrates is not simply one mani- 

 festation of their proteolytic activity. On this assumption the libera- 

 tion of the hemoglobin is regarded as due to the action of an enzyme 

 upon the stroma of the erythrocytes. Abbott and Gildersleeve,^ as 

 the result of their studies, reached the conclusion that "one may as 

 reasonably attribute the hemolysis exerted by these filtrates to the 

 action of their proteolytic enzymes upon the stroma of the erythro- 

 cytes as to any other factor." These authors take the liquefaction of 

 gelatin as the criterion of proteolytic action, and base their belief on 

 the identity of the hemolytic and gelatin-liquefying properties upon 

 certain general analogies. Opposed to this view are the observations of 

 Buxton^ and Eijckman,4 who found that the destruction of blood 

 corpuscles in blood-agar does not proceed pari passu with the lique- 

 faction of gelatin. The fact that many bacteria, such as B. coli,. 

 B. typhosus, and others, that are unable to liquefy gelatin can exert 

 a hemolytic action, has been considered an additional reason for not 

 identifying the gelatin-liquefying and hemolytic power of bacterial 

 filtrates. 



' Since writing the above, a paper by Tiraboschi {Ann. d' igiene sperim., 151, 905, p. 429; Abstr., 

 Bull, de rinsl. Pasl., 1905, 3, p. 922) has appeared which supports this position. 



' Jour. Med. Res., 1903, 10, 42. * Centralbl. /. Bakt., 1901, 20, p. 841. 



3 Amer. Med., July 25, 1903, p. 137. 



