234 IV. THE PRINCIPLES OF LIFE PHENOMENA 



high molecular proteins were produced in the same way as primeval 

 organisms ; primeval organisms might be different from usual pro- 

 teins only in their orderly polymerization. Possibly even at the stage 

 of primitive proteins there might also be a struggle for existence, 

 thereby weaker molecules were assimilized by the stronger, and thus 

 the evolution of proteins were established just as in the case of pri- 

 meval organisms. 



There seems no doubt, however, that such a "struggle for exis- 

 tence" among the protein molecules, when the proteins had not yet 

 been endowed with any highly evolved structure to produce a strong 

 structural influences, was only trivial, and accordingly their evolution 

 would be extremely tedious. The speed of evolution of assimilase or 

 of protein would be directly proportional to the differentiation degree 

 of the protein structure, and even when the proteins were able to 

 form orderly polymerized masses, the speed would increase with the 

 degree of differentiation of the polymerized mass, or assimilase. It 

 should be said, therefore, that the highly evolved creatures of the 

 present day may have the greatest speed of evolution and still now 

 be evolving most rapidly. This reasoning may naturally lead to the 

 view that the evolution of viruses which can make use of highly 

 evolved protoplasm for their matrix for evolution might be much more 

 rapid than that of the primary organisms. 



The very important fact discussed above that proteins are able to 

 exert their structural influences upon other proteins should be, on the 

 other hand, interpreted as indicating that proteins themselves are 

 enzymes, and therefore the evolution of proteins can be regarded as 

 the evolution of enzymes. As regards this view further discussions 

 will be made later. 



3. The Reason for the Presence of Optically Active 

 Amino Acids in Protoplasm 



Organic substances synthesized by organisms are always optically 

 active, as for example, amino acids constituting the proteins of 

 protoplasm are as a rule laevorotary, whereas optically inactive 

 racemic compounds are always yielded by artificial synthesis. 



This fact has long been regarded as one of the biological enigmas, 

 but this may naturally follow the crystal nature of the protoplasm. 

 The fact that optical isomers are distinguishable by their different 

 crystal shape has well been known since the brilliant finding of 

 Pasteur. Substances of dissimilar optical activities can by no means 

 exist in one and the same protoplasm. 



