II. THE PATTERN OF PROTOPLASM 233 



be called genes when exist in the cells of higher organisms. Genes, 

 therefore, are probably elementary bodies governing the structural 

 pattern of the protoplasm. 



If a primeval organism had a few number of such bodies, while 

 it mostly being composed of bodies rich in lipids, having no or little 

 nucleic acid, then the organism would be able to respond readily to 

 various stimuli without losing its original strong pattern. This must 

 be the splendid means by which the organisms could escape the dilem- 

 ma pointed out in the previous chapter. The most advanced means 

 along this line must be the gene system of the higher organisms of 

 the present day. Chromosomes which may be regarded as aggregates 

 of genes are actually confirmed to contain uucleic acid in rich amount 

 but without lipid (8). 



2. The Evolution of Protein Molecules 



Before discussing the problem of genes, it may be proper to make 

 some argument regarding the above mentioned phenomenon that 

 different proteins in a solution may exert mutual influences in the 

 establishment of an equilibrium system. That each component protein 

 in such a system can recover its own structural pattern on the isola- 

 tion, may be a natural result of the reversibility of protein structure. 

 However, it is noteworthy that adequate heating appears to render 

 the change irreversible as indicated in the above cited both findings 

 by Kleczkowski and by Zoet. If one component protein in a system 

 exerts a particular strong influence upon the other the pattern of the 

 system will be chiefly determined by the strong component. The 

 effect of some agent, like heating, on such a system may render the 

 change of the weaker components irreversible so that the change 

 may become durable, that is, the weaker component proteins may be 

 assimilized perpetually by the strong. 



The writer assumed that assimilase action is given rise to only 

 when protein molecules of the same type are orderly polymerized. 

 However, from what has been mentioned above, it may be said that 

 the assimilation is a general phenomenon occurring between different 

 types of proteins, although the assimilase action may only become 

 distinct on a regular polymerization ; in other words, it is considered 

 that protein molecules can act in themselves as assimilase upon other 

 molecules having weaker patterns. 



The synthesis in the primeval oceans of high molecular proteins 

 with a globulin nature might be possible on the basis of this pro- 

 perty of proteins as assimilase. Thus it seems most probable that 



