348 BACTERIOLOGY. 



the serum into a suppurative one, so that, by 

 sloughing off of the necrotic tissue local heal- 

 ing makes its appearance, and this is accom- 

 panied by the prevention of general infection 

 and poisoning. If the serum injection be de- 

 layed more than 36 hours, the local disturb- 

 ance may still frequently be healed, but, on the 

 other hand, general infection is not prevented 

 and is only retarded in its course. 



Clinging to his notion of a " passive " pro- 

 tective inoculation in which only the animal 

 producing the serum incurs risk, while the 

 animal receiving the serum reaps the benefit, 

 Behring has maintained with the greatest 

 positiveness the absolutely innocuous character 

 of the curative serum. But the statements 

 made above on p. 327 concerning the nature 

 of the anti-substances of the serum militate 

 against his view. If we accept Behring's 

 assumption of the purely specific nature of 

 the anti-substances, the fact that one com- 

 ponent of these substances is the bacterial 

 toxin itself, as the cases of Buschke and Mar- 

 cuse directly prove, is at variance with his 

 idea that the anti-sera are altogether harmless. 

 The following facts also are opposed to such a 

 belief. 



Favorable specific effects such as an im- 

 munity against living parasites and an habitua- 



