208 III. THE EVOLUTION OF VIRUSES 



undergone a change by some injurious agent is separated from the 

 normal protoplasm in forming an inclusion-like body which sometimes 

 is expelled from the cell. 



Yamafuji et al. (119) by applying peroxides have succeeded in 

 producing in silk-worms inclusion bodies similar to polyhedral bodies 

 peculiar to polyhedrosis. The generally confirmed mutagenic activity 

 of peroxides in microorganisms shows that protoplasm is liable to be 

 changed in its structure by these chemical agents. Of course, the 

 formation of an inclusion body must be entirely different from the 

 production of a virus. 



