CHAPTER VII 

 THE MODE OF VIRUS MULTIPLICATION 



1. Multiplication of Phage within Bacterial 

 Cell Protoplasm 



Many facts above cited have provided the basis on w^hich the 

 writer has formed the theory as regards the structure of protoplasm ; 

 meanwhile it may be said that these facts are supporting the theory 

 strongly, since they can be explained finely by the theory. On the other 

 hand, a vast number of facts have also been known concerning the 

 multiplication of viruses. Now, it must be mentioned how these facts 

 are to be interpreted by the writer's theory. 



Phage seems to be the virus with which the most profound and 

 most numerous investigations have ever been made, whereas some con- 

 clusions reached as to its multiplication by a number of workers ap- 

 pear to be inconsistent with what is expected from the theory above 

 mentioned. 



According to the writer's opinion, viruses are produced by the 

 rearrangement of polar groups in protoplasm protein, and therefore it 

 must be impossible that viruses are synthesized directly without con- 

 cerning protoplasm protein. Nevertheless, some workers reached a 

 remarkable conclusion that phage could be formed directly from 

 comiponents in the culture medium. For instance, a series of workers 

 in this field, such as Cohen and Putnam (96) (97), concluded that the 

 majority of elements in phage, such as phosphorus, were directly ori- 

 ginated from those contained in the culture medium. According to 

 Kozloff (98) about 75 to 95 per cent of phage protein nitrogen came 

 from the medium after infection, while remaining 5 to 25 per cent 

 were provided by bacteria. The writer is convinced, however, that 

 these conclusions are entirely incorrect ; the reasons are given in the 

 following. 



There are many evidences that only young bacteria are affected 

 by phage, aged bacteria being commonly insusceptible, and thus phage 

 can multiply, as a rule, only in young cells. First, the erroneous 

 conclusions might be reached because of neglecting of this fact; namely 

 since phage was produced by young growing bacteria which were 

 rapidly synthesizing the protoplasm from the components in the 

 culture media, the phage would be mistaken as being formed directly 



