306 Chapter X 



played by Pfeiffer's phenomenon is very limited. The destruction 

 of the vibrios is effected with certainty, and completely, under the 

 influence of the specific serums, not by a direct action of the two anti- 

 bacterial substances but through the mediation of the phagocytes. 

 Before the fixative, introduced with the protective serum, can bring 

 about this result, the leucocytes, impressed with a special sensitive- 

 ness, must come up to the seat of inoculation, seize the micro-organisms 

 and secrete around them their cytase. It is only as a result of these 

 actions, purely vital, that the chemical or physico-chemical reaction of 

 the substances which intervene in the destruction of the vibrios is 

 brought about. 



Under these conditions it can easily be understood that if the 

 vital action of the phagocytes is retarded or depressed the injection 

 of protective serum cannot preserve the life of the animal. Canta- 

 cuzene 1 , who had already made a similar demonstration on guinea-pigs 

 vaccinated against the cholera vibrio by these organisms or by their 

 products, carried out numerous experiments on the action of opium 

 on normal guinea-pigs simultaneously inoculated with vibrios and 

 specific serum. Before injecting this mixture Cantacuzene narcotised 

 his animals by means of tincture of opium. The great majority (f) 

 of the guinea-pigs so treated died at the end of one or several days. 

 The transformation of the vibrios into granules, under the influence 

 of the serum, took place in the peritoneal cavity, but the leucocytes, 

 on account of the narcotic action of the opium, were tardy in coming 

 up. On their arrival in the peritoneal cavity they were capable of 

 [322] ingesting the granules, but absolutely refused to seize entire vibrios, 

 always fairly numerous in the exudations. In spite of the appearance 

 of a large number of leucocytes, these cells were still too weak to 

 offer any adequate opposition to the vibrios, which increased in 

 number and continued to multiply up to the death of the animal, 

 when the exudation simply swarmed with very motile vibrios. Some- 

 times the struggle was prolonged. The weakened leucocytes allow 

 the vibrios to develop, but, after a greater or less length of time, 

 they regain their strength and begin to ingest the micro-organisms 

 vigorously. Complete phagolysis follows, but the guinea-pig, attacked 

 by the toxic products of the vibrio, finally succumbs in spite of the 

 absence of free vibrios from its body. 



An analysis of the phenomena observed in the body of an animal 

 treated with antivibrionic serum, demonstrates that, in spite of a 

 1 Ann. de Vlnst. Pasteur, Paris, 1898, t. xn, p. 290. 



