MOVING PHOTOMICROGRAPHY— KAZEEFF 



333 



reticulocytes which are capable of destroying bacteria by engulfing 

 them in the same fashion as do the phagocytes. 



To Metchnilvoff belongs the great merit of bringing to light the 

 role of the phagocytes in the natural defense of the organism, but 

 contrary to his opinion, this means of defense is not the only one. 

 Its interpretation, which is too exclusive, raised numerous contradic- 

 tions, especially in Germany. It caused a true scientific war of 30 

 years. While Metchnilcoff and his pupils insisted that the principal 

 factor of immunity is phagocytosis which engulfs the microbes and 

 digests them, Baumgarten, Ziegler, EhrUch, Behring, Pfeiffer, and 

 others insisted that the principal factor of immunity rests in the 

 bactericidal action of the humors and the blood of the organism (the 

 humoral theory). 



Figure 3.— The Pfoiffer phenomenon. At left, motile cholera vibrios in the peritoneal exudation of a young 

 guinea pig; at right, agglutination and granulation of the vibrios in the exudation of an immunized guinea 

 pig. 



HUMORAL DEFENSE 



Pfeiffer contributed by the following demonstrations the first 

 experimental arguments supporting the humoral theory. 



If the peritoneal exudation of a guinea pig is collected a half hour 

 after an emulsion of cholera vibrios have been injected into its peri- 

 toneum, these vibrios present their usual appearance; they are motile 

 and independent of each other. If a similar operation is made on a 

 guinea pig which some time before has received a nonmortal dose of 

 the same cholera vibrios, the vibrios become agglutinated, immobilized, 

 having lost their form and present a granular aspect. It is evident 

 that the blood serum of the organism immunized (in this case probably 

 vaccinated or artificially immunized) against the cholera bacillus has 

 acquired the power to destroy the microbes of this infection. This 

 is the classical phenomenon of bacteriolysis (fig. 3). 



Buchner, pui-suing these studies, discovered natural haemolysis. 

 If some red blood corpuscles of the sheep are introduced into serum 



