194 MANUAL OF BACTERIOLOGY. 



blood-serum. But whether normally present or not, specific 

 lysins, like specific agglutinins, are made to appear in the blood- 

 serum of animals by injecting these with several doses of sus- 

 pensions of cells. Hemolysin results from injecting an animal 

 with the red blood-cells from another animal, bacteriolysin from 

 the injection of bacteria. The serum of the blood of animals 

 injected in this way is called immune serum. Thus an animal in- 

 jected with B. typholococcus furnishes typhoid-immune serum; 

 an animal injected with rabbit's blood-corpuscles furnishes 

 rabbit-corpuscle-immune serum. Hemolysins and bacterio- 

 lysins are quite sharply specific. A rabbit injected with a 

 suspension of red corpuscles from the blood of a guinea-pig 

 furnishes hemolysins which destroys guinea-pigs' red cells. 

 A guinea-pig injected into the peritoneal cavity with repeated 

 small doses of the cholera spirillum furnishes a peritoneal 

 fluid containing a bacteriolysin specific for the cholera spirillum. 

 Still, group lysins, like group agglutinins, are also found, for 

 while lysis takes place more promptly and in smaller amounts 

 with the cells of the same species of animal or with the same 

 kind of bacteria with which the animal furnishing the cytolytic 

 serum has been injected, it also occurs in a less marked degree 

 with cells from nearly related animals or with nearly similar 

 bacteria.* 



The same serum is not equally potent for different bacteria, 

 and the serum from different animals of the same or of different 

 species varies in bactericidal potency for the same organism. 

 The chemical reaction of the serum seems to exert some effect 

 upon this quality of the serum. The more alkaline the serum 

 the more potent is its action apparently, 'and consequently 

 the venous blood has been found sometimes to furnish more 

 potent serum than the arterial blood from the same animal. 



Serum loses in bactericidal potency on standing after being 



*Further reference: Pribram. KoUe and Wassermann. Erganzungsband 

 1906. pp. 291-346. 



