108 ACTIVITIES OF BACTERIA. 



seen of the vibriones except single granules, and these 

 are not always easily found, and the peritoneal contents 

 have become viscid, mucoid, and tenacious. If the re- 

 sult is negative, the peritoneal exudate after an hour con- 

 tains large numbers of actively motile vibriones. It is 

 recommended that a control test be made upon a second 

 animal with the same bacteria and normal serum. Normal 

 serum at most causes in quantities of 0. 1 c. c. and upward 

 a very slight positive reaction — i. e. , it causes a few vibri- 

 ones to undergo granular degeneration (compare R. PfeifTer 

 and Kolle, C. B. xx, 129). 



R. PfeifTer and Marx (C. B. xxm, 858) have shown 

 the places of origin of the bactericidal bodies to be the 

 spleen, and also the bone-marrow and lymph-glands, 

 which possess specific bactericidal action much earlier 

 than the blood. Rath (C. B. xxv, 549) could not make 

 the same demonstration regarding agglutinin. 



According to Max Gruber and Bordet, the action under 

 1 and 2 does not differ in principle. Their extremely 

 simple theory, recently confirmed in the essential points 

 by Trumpp (A. H. xxxm, 70), is as follows: 



In immune serum substances are present which cause 

 the bacterial cells (especially their membranes) to 

 swell, thus, without killing them, interfering with their 

 motion and causing them to stick together. 1 In this 

 weakened condition of the bacteria, the alexins of the 

 body act as powerful bactericides. According to Gruber 

 and Trumpp, also, the bactericidal action depends upon 

 the combined effects of the agglutinin and the alexin. 

 Trumpp proves this view by showing that also in vitro 

 bacteria which are swollen, paralyzed, and clumped 

 under the action of immune serum are killed by contact 

 with the fresh serum of healthy animals. Also, Land- 

 steiner's investigations are in accord with this (0. B. xxm, 

 847). f 



While this sounds so exceedingly simple, still there are 

 a series of observations which speak in favor of the view 



1 According to Paltauf and Nicolle, the agglutination is to be 

 explained by a cementing over of the bacteria by a precipitate which 

 is produced by the serum. (Compare Kraus and Seng, Wien. klin. 

 Wochenschr., 1899, 1.) 



