X. THE SECONDARY ORGANISMS 207 



If a virus structure was readily assimilized and destroyed by the 

 normal structure when existed in separate particles, whereas in a 

 large aggregated state it was stable and could resist the assimilase 

 action of the protoplasm, then the large mass only would remain as 

 the virus. In view of the virus nature already discussed such an 

 occurrence seems highly probable. 



The shape of inclusion bodies are said occasionally to tend to be 

 peculiar to the kind of viruses and of the host cells. Since the bodies 

 formed by the aggregation of virus particles may be regarded as a 

 kind of liquid crystals like the protoplasm, the shape may naturally 

 be exerted some influences by the kind of protoplasm as well as the 

 sort of the virus. The shape accordingly may change with the host cell 

 as well as with the virus. It should be remembered that the shape of 

 crystals is, as a rule, determined by the solvent or the environment, 

 in which they are formed, as well as by the component substance 

 of the crystal. 



If some viruses or some microorganisms could exist only in a form 

 like that of inclusion bodies, they would vary their shape with the host 

 or with the surrounding condition. This may be the reason why para- 

 sitic microorganism, existing in the .form of virus-aggregate, alter 

 their shape whenever they change the host. As already stated, the 

 protoplasm can be regarded as a virus-aggregate or a mass composed 

 of elementary bodies. The mechanism of metamorphosis may thus 

 be developed. 



The earlier workers regarded inclusion bodies of some viruses as 

 protozoa, and pictured them as varying stages of an elaborate life-cycle. 

 From the above point of view, it may be said that this supposition is, 

 in a sense, correct. In fact, at present, the majority of workers con- 

 sidered that highly advanced viruses such as those of psittacosis and 

 lymphogranuloma undergo a developmental life cycle, in which virus 

 particles or elementary bodies enter a cell, and then increase in size 

 to become initial bodies ; a larger form of inclusion known as a plaque 

 or morula is then formed from the initial bodies, and comes to con- 

 tain large numbers of elementary bodies, which eventually rupture 

 from the cell (118). This phenomenon can be interpreted as "crystal- 

 lization " of virus particles or elementary bodies in the host proto- 

 plasm into larger bodies, which are decomposed when the environ- 

 mental condition is changed. 



It follows from the theory of the writer as regards the nature of 

 protoplasm and virus that inclusion bodies should be produced by 

 proper chemical or physical agents other than viruses, if structural 

 changes similar to those induced by virus are given rise to in the 

 protoplasm. In fact, it is known that a part of protoplasm having 



