﻿IMMUNITY RESEARCH. 355 



Doerr(5) also thinks that Bail is dealing with dissolved bacterial sub- 

 stances, as he obtained the precipitin reaction with aggressive exudates, 

 and he brings forward criticism against the work of Bail, on the score 

 of the inaccuracy of the so-called sublethal doses. He also found that 

 aggressins are of themselves injurious, and that one aggressin promotes 

 infection with a different species of bacillus. 



Levy and Pornet(7) were able to demonstrate the aggressive nature 

 of filtrates of 24- -to 48-hour bouillon cultures of typhoid and paratyphoid 

 bacilli. They found that these filtrates were "infection-promoting" to 

 the extent of increasing fivefold the virulence of typhoid bacilli. The 

 addition of filtrate or exudate aggressin to leucocytes blocked the phago- 

 cytic power against typhoid bacilli, which was otherwise present. 7 



Ballner(3) found that nonbacterial exudates obtained from guinea 

 pigs increased the infectious action of Friedlander's bacillus in rabbits, 

 in other words exercised an aggressive action. He could not obtain an 

 anti-aggressin immunity with this germ. 



Wolff-Eisner (13) reviews the aggressin literature at length and con- 

 cludes that the aggressins are nothing but endotoxins from bacteria; 

 that they alone are not present in sufficient amount to act strongly, but 

 that, upon addition of fresh bacteria, a summation effect is obtained and 

 the animal dies quickly. He thinks this also explains the negative 

 chemiotaxis occurring with aggressins. 



What part the aggressin plays in the blocking of leucocytosis is also 

 in dispute. Citron, in studying meningococcus found that there was 

 no relationship between aggressivity and power to block phagocytosis, 

 while Salus' work raises the question as to whether the aggressin action 

 is anti-chemiotactic at all, as the aggressin acts even though it is injected 

 in a different part of the body from the bacteria. 



On the other hand, Bail and his school have published a series of 

 articles dealing with the aggressins in cholera, typhoid, dysentery, plague, 

 tuberculosis, Bacillus subtilis, chicken cholera, hog cholera, pneumococ- 

 cus and staphylococcus. 



Bail has satisfied himself that aggressin action occurs in tuberculosis 

 also, although in this case active phagocytosis continued after addition 

 of aggressins. Koch long ago obtained the same action by the use of 

 dead cultures, thus ruling out any vital action in the production of 

 aggressins. 



The last article from Bail is a lengthy rejoinder to the criticism of 

 Wassermann and Citron. He contends that the extracts used by Was- 

 sermann and Citron are altogether different from aggressins, and that 



7 Concerning Bail's statement that the aggressive property of body fluids is 

 due to secretion products from bacteria, see v. Pirquet and Shick, "Die Serum- 

 krankheit." Wien, 1905. 



