BACTERIOPHAGE AS AN ANTIGEN 397 



7. THE COMPLEXITY OF AN ANTIBACTERIOPHAGIC SERUM 



The antibacteriophagic property which appears in the serum when 

 an animal is injected with a suspension of the bacteriophage is neces- 

 sarily produced because of a reaction by the animal to the bacterio- 

 phage protobe. But a bacteriophage suspension contains not only 

 protobe substance, but other materials as well, such as : 



1. The dissolved substances of the bacterial bodies. 



2. The products resulting from bacteriophagy, no matter whether 

 they are elaborated by the protobes or by the bacteria.* 



3. Products elaborated in the physiology of the bacteria prior to 

 their dissolution, such as the toxins. 



The antibacteriophagic serum must, therefore, contain a complex 

 of antibodies, and, as a matter of fact, various antibodies have been 

 demonstrated. In their early work with the sera Bordet and Ciuca^^ 

 showed that such a serum had agglutinating properties for the bacterium 

 bacteriophaged, as well as precipitating properties. With EUava^^^ I 

 found that it also contained a sensitizer for the bacterium concerned. 

 Wollman and Goldenberg"^^ have shown that the antigenic value of 

 the bacterial substances dissolved through the action of the bacterio- 

 phage is superior to the antigenic value of normal bacteria. 



These facts make it evident, and this is a point of some significance 

 from the point of view of the nature of the bacteriophagic process, 

 that the greater part of the bacterial substance can not have under- 

 gone any great modification in the sense of a degradation during the 



* That such products exist is proved by a number of the experiments described 

 in Part I of this text, among others, by the experiment showing the absence of 

 bacteriophagy in gelatin media because of the accumulation of these products at 

 the surface of the medium. It may be recalled that this inhibition is due to the 

 non-diffusibility of these substances into the gelatin, since on a layer of gelatin 

 superimposed upon a substratum of agar, bacteriophagy takes place normally. 



In the text The Bacteriophage, Its Role in Immunity^-' I suggested that in 

 bacterial suspensions which had undergone bacteriophagy there might be present 

 both "lysins" elaborated by the bacteriophage and "antilysins" elaborated by the 

 bacteria. I recognize, as I have already said, that such an inference can not be 

 experimentally confirmed, and that at the present time, it is impossible to show 

 that such products exist. 



On the contrary, and here experiment is conclusive, in a bacteriophaged bacterial 

 suspension there are abnormal substances which do not appear either in old cul- 

 tures of bacteria or in autolysates. These substances appear only because of the 

 presence of the bacteriophage, although there is no indication as to their origin. 

 That is why I have designated these substances as "products resulting from 

 bacteriophagy." 



