IV. THE SUPREMACY OF GENES 247 



Other granules. 



' It is generally accepted that vigorous propliferation of cells is 

 usually accompanied by a marked increase in nucleic acids. This 

 may mostly be attributed to the unbalance in the mixed proportion 

 caused by the increase of nucleic acid. It seems that some structural 

 change in protoplasm may lead to the increased capacity of the pro- 

 toplasm to combine with nucleic acids, as for example, mechanical 

 injuries or chemical stimuli cause the increase in nucleic-acid content 

 •of the cell. Such nucleic acid increase would naturally bring about 

 the vigorous synthesis of protein in order to alleviate the unbalance in 

 the mixed proportion ; this may account for the well known fact that 

 various stimuli generally lead to the marked proliferation of cells. 



The virus infection, in general, may bring about the nucleic acid 

 increase in the cell. For instance, when bacteria are affected by phage 

 nucleic acid, especially DNA, markedly increases (33). During the 

 course of normal growth the cells of E. colt synthesize almost three 

 times as much RNA, but susceptible cells suspended in a synthetic 

 medium and infected with phage will show a rate of DNA synthesis 

 approximately four times as great as that observed in normal 

 cultures. This may suggest that the structural disturbance in the 

 bacterial protoplasm caused by phage may alter the mixed proportion 

 of DNA to the protein. 



If a structural disturbance in the protoplasm caused by some 

 stimulus resulted in the increase in nucleic acid, especially in DNA, 

 the structural change, if occurred after the disturbance, would be well 

 retained in the protoplasm particles, because these particles would be 

 endowed with strong structure and accordingly with powerful assimi- 

 lase action owing to the high content of the nucleic acid so that they 

 might be able to act as a newly produced virus. When this virus 

 affects some cells to produce the replica, in the protoplasm of the 

 cells will be raised the structural disturbance which may cause the 

 same nucleic acid increase, since the virus structure may have the 

 property to cause the increase in nucleic acid. This may be the reason 

 Avhy nucleic acid is increased in the cells affected by a virus. A 

 virus which failed to cause a change leading to a marked nucleic acid 

 increase in the protoplasm would not be able to continue to exist. , 



Lysozyme can cause lysis of bacteria like phage, but fails to 

 multiply. The characteristic chromatic granules of the bacteria are 

 seen on the phage infection indicating the occurrence of striking 

 change in the nucleic acid, whereas lysozyme fails to induce any 

 similar change in the granules (34). The inability of lysozyme to 

 become a virus would be accounted for partly by this failure to in- 

 fluence the nucleic acid content. In the presence of proflavine bacteria 



