VIII. THE INHERITANCE OF ACQUIRED CHARACTE?. 390 



change corresponding to a given environmental factor will be produced 

 in the cells or tissues upon which the factor is directly supplied ; and 

 such a specific change may be unable to be transmitted to the germ 

 cells by hormones. However, if the specifically changed structure of 

 the protoplasm is liberated from the cell in the form of a "virus" the 

 structure will be easily transmitted to the germ cells. 



In ontogeny, as was already considered, the development of proto- 

 plasm structures inducing the advancement of various characters are 

 apparently achieved by both hormones and virus-like agents. It may, 

 therefore, be reasonable to suppose that in phylogeny also virus-like 

 agents, in addition to hormones, are involved, since the miniature of 

 phylogeny is seen in ontogeny. 



It is most interesting that this concept is well in accord with 

 Darwin's pangenesis theory. Darwin considered that minute particles 

 termed gemmules may be distributed throughout the body of the 

 organism in order to accept external effects and subsequently to 

 transmit them to germ cells. Of course, gemmules are no more than 

 "viruses" in the writer's concept. 



It was already pointed out that primitive structures of the proto- 

 plasm are unstable and weak, as the primitive structures are the 

 newly produced as compared with the differentiated ones. Chick em- 

 bryos have primitive structures and so can readily affected by various 

 viruses. In a similar way, since germ cells or mother germ cell are 

 of primitive nature, their structural pattern will be readily changed 

 by the "viruses" or gemmules. Consequently, environmental effect 

 may be easily transmitted to germ cells or mother germ cells through 

 virus-like agents. 



The structural correlation between soma and germ cells or mother 

 germ cells, suggested in Chapter I, 3, in this Part, can be thus 

 achieved by "viruses." The genes in germ cells are considered, there- 

 fore, to be always accepting the structural pattern of every part of the 

 body through the "viruses" ; and accordingly the genes in the germ 

 cell must be the representatives of all patterns of somatic cells. The 

 patterns engraved in the genes will be developed during ontogeny 

 when the conditions become fitted for their development. 



To sum up, if certain somatic cells are changed in their protoplasm 

 structure by a certain environmental factor, the changed structural 

 pattern will be transmitted by the "virus" to the germ cell; and the 

 character corresponding to the pattern will be developed in the pro- 

 geny, if the pattern is strong enough not to be returned to its original 

 during the development. 



Hormones may be able to induce striking changes in the structure 

 of the genes, but their action is rather non-specific as compared to the 



