542 BACTERIOliuGY. 



of instances antitoxic activities are acquired peculiarities ; 

 acquired in some cases in a more or less natural manner, 

 as in the course of a non-fatal attack of a specific mal- 

 ady: induced in others by purely artificial means, as 

 we have seen to be possible in the case of diphtheria, 

 tetanus, etc. Our acquaintance with these bodies ex- 

 tends little further than their physiological functions 

 and some of the means that induce their genex'ation. 

 We have no satisfactory knowledge of their intimate 

 nature or of the primary sources of their production. 

 They are believed by some (Buchner' and Metschnikoff ^) 

 to represent, when artiiicially induced, bacterial toxins 

 that have been modified by the vital action of the inte- 

 gral cells of the body; and Roux^ and Buchner* hold 

 that they exhibit their protecti\'e functions less by 

 direct combination Avith the toxins than by a specific 

 stimulation of the tissue-cells that enables the latter to 

 resist the harmful influences of the poisonous bacterial 

 products. On the other hand, Behring,^ Ehrlich,^ and 

 their associates contend that they are vital tissue ele- 

 ments, having the property of combining directly with 

 the toxins to form " physiologically neutral " toxin-anti- 

 toxin compounds that are in a manner analogous to the 

 double salts of certain chemical reactions. 



No. 8. Fisohl and y. Wunschlieim ; Centralblatt fiir Bakteriologie, 

 Parasitenkunde, und Infektionskrankheiten, 1896, Abt. i. Bd. xix. S. 

 652. Wassennann: Berliner klin. Wochenschrift, 1898, No. 1. 



1 Buchner : Miincliener med. Wochenschrift, 1893, Nos. 24 and 25. 



^Metschnikoff: Weil's Handbuch der Hygiene, Bd. ix. Lieferung 1, 

 S. 48. 



5 Eoux : Annales de 1' Institut Pasteur, 1894, p. 722. 



* Buchner : Berliner klin. Wochenschrift, 1894, No. 4. 



' Behring : Infektion und Desiufektion, Leipzig, 1894, S. 248. 



«Ehrlich: Klinisches Jahrbuch, 1897, Bd. yi. Heft 2, S. 311. Fort- 

 schritte der Medicin, 1897, Bd. xv. No. 2. 



