72 Heredity and Social Progress 



assumptions. Organisms are bilateral. The 

 parts of the brain are duplicated and the right 

 and left sides of the body are similar. Bodily 

 actions are in rhythms which, by being pleas- 

 urable, help to sustain life, while any move- 

 ment out of rhythm is painful and destructive. 

 Many philosophers make rhythm a funda- 

 mental law of the universe, but even without 

 such an extensive application, the validity of 

 the thought may easily be verified in organic 

 processes. The love of music, the harmony of 

 colors, and the constant desire to replace each 

 sensation, feeling, or emotion by others, all 

 indicate how important this principle is. If it 

 is not a condition of life, it is at least an im- 

 portant secondary law and in this form it will 

 serve my purpose. 



Professor Weismann has made emphatic 

 the difference between the germ cell and the 

 somatic cells derived from it. Although the 

 germ cell can influence the somatic cells, yet 

 they, in turn, cannot alter its structure. It 

 retains its full responsiveness and hence can 

 reflect in itself the essence of the changes in 

 the somatic cells. It has, therefore, the condi- 



