THE SUMMARY OF PART V 443 



local structure is so fixed as to be called an organizer, a series of 

 peculiar structures are formed around it, with the formation of com- 

 plicated shapes and functions. 



The structures thus varying with the portion of an individual are 

 produced because the local genes have been changed in their structure 

 by the environmental effects which vary with the portion. Therefore, 

 every organ and tissue must have peculiar genes. This conclusion 

 seems natural, since, as is generally accepted, every organ is provided 

 with protein antigenically specific to the organ, while it is also be- 

 lieved that what determine the protein structure are genes. 



The so-called biogenetic law that ontogeny recapitulates ph^dogeny 

 can also be readily explained by the assumption that the germinal 

 cells are the reductive form of the somatic cells, and the change 

 giving rise to reduction is reversible. Since the structural reversibility 

 of a protein is considered to be based upon the memory of the course 

 along which the protein has attained to the present structure, the 

 somatic cells, in the course of reduction to the germinal, have to 

 pursue reversely the course of phylogeny, whilst, in the coui'se of 

 development of the germ cell, the course of phylogeny itself is to be 

 followed. This reversible change must be repeated in each generation, 

 and hence the memory is correct, and ontogeny recapitulates phylogeny 

 without fail. 



In higher animals, it seems that the memory is retained only in 

 the particular cells involved in the production of germ cells, and in 

 ordinary- somatic cells there appears to be some mechanism by which 

 the reduction of the structure is made difficult. Ordinary cells are, 

 however, also inclined to be reduced to the primitive structure when 

 the preventing mechanism is rendered weak, and in such a case cancer 

 cells, the structure of which is primitive like germ cells but different 

 in many respects from the latter presumably on account of this 

 abnormal reduction, are produced. Sexual hormones play an important 

 role in the production of germ cells, whilst the same hormones or 

 related substances appear to be involved in the production of cancer 

 cells. The reduction of somatic cells to cancerous is an abnormal 

 process and so the return of the cancerous to somatic cells appears 

 to be not an easy occurrence as in germ cells, but it does sometimes 

 occur. 



The structural reversibility of genes is extremely strong. The 

 genes have the property to alter their structure according to the 



