138 THE BACTERIOPHAGE 



ANTIBODIES TO THE LYSINS 4 



We have already seen that it is possible to obtain lysins without 

 admixture with viable bacteriophagous ultramicrobes by pre- 

 cipitating a culture of the bacteriophage with alcohol. 



Since growth of the bacteriophage takes place within the in- 

 terior of the bacteria the ultramicrobe can effect its penetration 

 only by corroding the wall of the bacterium in order to make way 

 for its passage, and it is evident that it can do this only by means 

 of a lysin. If the antibacteriophage serum contains an antilysin 

 it is evident that the penetration will be retarded or even pre- 

 vented by the presence in the medium of the neutralizing serum. 

 And this delay or prevention, according to the amount and po- 

 tency of the serum, will be associated with a delay or prevention 

 of the lysis, since the ultramicrobes will be unable to penetrate 

 the bacterial cells. The antibacteriophage serum will assure, in 

 a word, the protection of the bacteria, without actually exercis- 

 ing any action on the vitality of the virus itself. This is, in fact, 

 what is actually observed. 



The antibacteriophage serum used in these experiments pos- 

 sessed a considerable inhibiting power; 0.00001 cc. added to 10 cc. 

 of a suspension of dysentery bacilli this is one-millionth of the 

 final volume markedly retarded lysis. With 0.001 cc. lysis 

 was prevented. Obviously, this fact might be interpreted as a 

 destruction of the bacteriophage pure and simple. But this 

 would be indeed strange in view of the fact that a serum has never 

 destroyed a bacterium in vitro, even in the presence of comple- 

 ment. I know that this affirmation is contrary to universal 

 opinion touching the bacteriolytic action of antisera, but in 

 Part II of this work I will show the foundation for it by an ex- 

 periment which permits of no doubt. 



In so far as the action of an antibacteriophage serum upon 

 lysis is concerned, the following experiment shows that the bac- 

 teriophage is not destroyed; its action is only inhibited. 



4 To repeat what is meant by lysin : The aggregate of the secretions of 

 the bacteriophage, without prejudging that they operate as a diastase only, 

 or as a collection of diastases, as is more probable. It has been shown in 

 an earlier chapter that the bacteria, like higher organisms, react to the 

 lysins by the production of antilysins. 



