136 GENETIC VARIATIONS 



earlier work* the present author has developed the view that 

 such adaptive action must be due fundamentally to selective 

 action occurring within the tissues of the organism. If there is 

 such action, it occurs as well in the genie materials of unicel- 

 lular organisms as in the somatic tissues of higher forms. 



Does the fact that environmental effects and reactions are 

 inherited in Protozoa, giving rise to adaptive and progressive 

 inherited characteristics, suggest that we should eventually 

 expect to find this method of operation in the higher 

 organisms ? 



Perhaps the most important feature in the genetics of the 

 Protozoa is the demonstration that the genie materials pos- 

 sess here the same powers of direct acclimatization or immu- 

 nization to injurious agents that are possessed by the somatic 

 tissues of higher organisms. Genie materials are materials 

 that assimilate and reproduce, each true to its type. The facts 

 in the Protozoa show that after the genie materials have 

 undergone an adaptive change, they may assimilate and 

 reproduce in the changed condition, resulting in inheritance 

 of the change. There is thus no incompatibility between the 

 acquirement of adaptive changes and the capability of assim- 

 ilation and reproduction in the changed condition; for these 

 things occur in the same material in lower organisms. There 

 is no inherent impossibility in this method of operation. 

 There is thus no general reason why it should not occur in 

 higher organisms; no a priori reason why the germ cells of 

 higher animals should not thus acquire certain adaptive 

 characteristics, and hand them on to descendants. Whether 

 they do or do not is simply a question of fact, to be deter- 

 mined by observation. If the higher organisms differ from 

 the lower ones in this matter, it is because of special condi- 

 tions operating in higher organisms. 



