224 Chapter VIII 



chamber of the eye, where Pfeiffer's phenomenon is regularly absent, 

 the phagocytosis follows its ordinary course and causes the destruction 

 of the vibrios. This result has been confirmed repeatedly — see works 

 by Bordet, Mesnil and Salimbeni already quoted. 



We need only compare the extension of Pfeifier's phenomenon 

 and that of phagocytosis in animals that are immunised against the 

 cholera vibrio, to satisfy ourselves that the former phenomenon is a 

 limited one whilst the latter is general. There might be advanced 

 against the latter conclusion the fact of the absence of any ingestion 

 of the vibrios in the peritoneal fluid of guinea-pigs that are im- 

 [236] munised but are not preserved against phagolysis. When a little of 

 the peritoneal fluid is drawn ofi" with small tubes shortly after the 

 injection of vibrios into the peritoneal cavity, as a matter of fact, only 

 a very intense Pfeiffer's phenomenon is seen, phagocytosis being com- 

 pletely or almost entirely absent. But this procedure is insufficient. 

 If we are to get an idea of what really takes place in the abdominal 

 cavity, the animal must be killed and the peritoneum and especially 

 the omentum very carefully examined. As flrst demonstrated by 

 Max Gruber^ and later by Cantacuzene^, the greater omentum is, in 

 these cases, covered with a thick layer which contains a large number 

 of leucocytes, of which some are filled with vibrios ; further, this 

 layer contains a mass of vibrios, in part transformed into granules, 

 in part agglutinated or isolated and retaining their vibrionic form 

 intact As time goes on, the phagocytosis becomes more and more 

 marked, and it is impossible to deny its existence or to attribute to 

 it merely a secondary part. 



We have seen that the suppression of Pfeiffer's phenomenon in 

 the peritoneal cavity and in the blood, or its total absence in the 

 anterior chamber of the eye, does not in the least deprive the vac- 

 cinated guinea-pig of its acquired immunity. The animal resists 

 the vibrios perfectly, without these requiring to be transformed into 

 granules in the body fluids. This transformation does take place 

 undoubtedly, but only inside the phagocytes. As already stated in 

 the discussion on natural immunity (Chaps. VI, VII) the vibrios, 

 after being ingested by the microphages, almost immediately undergo 

 within these cells a change in form, very similar to that observed in 

 the real Pfeiffer's phenomenon. The microphages are often full of 

 a quantity of granules, derived from the ingested vibrios, which in 



^ Miinchen. med. Wchnschr., 1896, SS. 277 and 310. 

 2 Ann. de VInst. Pastew^^ Paris, 1898, t. xn, p. 273. 



