406 THE BACTERIOPHAGE AND ITS BEHAVIOR 



Hauduroy.2^^ He immunized a number of young rabbits, weighing 

 from 1300 to 1700 grams, giving them a series of 7 injections of a sus- 

 pension of the Staphylo-bacteriophage. All injections were made 

 subcutaneously, at 5- to 6-day intervals, and 2 cc. of the suspension 

 were given on each occasion. The bacteriophage used was of maximum 

 virulence. The suspensions were filtered, and were held for at least 

 15 days to prove their sterility before they were used. 



Other rabbits, which were to serve as controls, received a like num- 

 ber of injections of sterile bouillon. 



Considering the effects as they developed during and after this 

 treatment, the results may be divided into two groups: 



First group : A number of the rabbits became emaciated very quickly, 

 and died, either before or immediately after the series of 7 injections 

 was completed. At autopsy Hauduroy never found staphylococcus 

 lesions of the organs in these animals, but always multiple subcutaneous 

 abscesses due to staphylococci. When these abscesses ulcerated the 

 lesion did not appear, in any case, to show any tendency toward a 

 spontaneous cicatrization. 



Second group : The other animals increased in weight in an approxi- 

 mately normal fashion throughout the entire course of treatment. 

 Abscesses never appeared. But if, a few days after the last injection of 

 the bacteriophage, these apparently healthy "immunized" rabbits 

 were given intravenously a dose of the staphylococcus which was never 

 fatal for the controls, they died within 24 hours, and the staphylococcus 

 injected could be recovered from the heart blood. 



The control rabbits, that is, those which had received the injections 

 of bouillon, increased in weight normally, showed no abscess formation, 

 and resisted intravenous injections of the staphylococci. 



This experiment of Hauduroy is very interesting, for it shows that 

 antiphylaxis, developed by a series of injections of a suspension of the 

 bacteriophage, may be so potent that the animal may lose its natural 

 immunity to a bacterium. 



Confirming this significant finding, I also have observed upon several 

 occasions the marked emaciation and spontaneous death of rabbits 

 as a result of a series of injections of suspensions of the Staphylo- 

 bacteriophage. At autopsy these animals presented most often, as 

 in the experiments of Hauduroy, subcutaneous abscesses. On two 

 occasions I have found miliary abscesses of the liver. 



Not all races of the bacteriophage possess the property of causing 

 antiphylaxis, and, curiously enough, the capacity to incite this reaction 



