122 II. FUNDAMENTAL STRUCTURE OF PROTOPLASM 



photographed unless brought under proper conditions, and occasionally 

 even revealed in shapes entirely different from the actual ones. 



6 



Viruses are commonly believed in chemical nature to be nucleo- 

 proteins. The writer claims, however, that the pattern of virus-tem- 

 plate is originally determined by the structure of protoplasm protein 

 of a globulin nature, nucleic acids having nothing to do with the 

 pattern. The effect of the template is enhanced by the polymerization 

 of the protein molecules, but if nucleic acids are inserted among these 

 molecules, the polymerization products, /. e., the virus particles, 

 may become stable and rigid in the configuration so that the template 

 action may be strengthened. In the particles without nucleic acid the 

 mutual combination of the protein molecules is loose, and consequently 

 the structure of particles are so unstable as to be readily destroyed 

 and in addition the templating action itself is insignificant. 



On the other hand, when nucleic acids are contained in the particle 

 to make its structure rigid, ,the particle may become more easily 

 sedimentable, so that by means of the ultracentrifuge particles con- 

 taining nucleic acid in rich amount may be readily isolated, and 

 again since the virus activity is mainly to be retained in these particles 

 for the reason just mentioned, only particles containing nucleic acids 

 in rich amount may come, as a natural result, to be considered as 

 viruses. 



Lipids, in contrast to nucleic acids, if contained in the particle,, 

 may render the structure easily changeable, and consequently may 

 have an unfavourable influence upon the viruses against their action. 



Since the function of viruses is to act as the template, lipids are 

 not only unnecessary but rather deleterious, whereas for the proto- 

 plasm in which the replica is to be produced lipids are indispensable. 

 In short, the free motion of protein structure in the protoplasm, a 

 motion which is considered to be essential for the development of life 

 phenomena, can be achieved only by the presence of lipids, whilst the 

 motion may be hindered by nucleic acids. Therefore, particles con- 

 taining great quantities of nucleic acids but little or no lipids are 

 fitted to act as the template, so that such particles are liable to be 

 regarded mainly as viruses. 



