WHY WAS THIS THEORY NOT STATED BEFORE 269 



before the Royce Club, Harvard University), ex- 

 pressed himself thus: 



"Most geneticists regard chromosomes as the 

 bearers of hereditary qualities in organisms. But 

 in the physiological sense no such theories of 

 heredity can be regarded as ultimate; if chromo- 

 somes (e.g.) determine the appearance of certain 

 special characters in organisms (as now appears 

 almost certainly to be the case) what determines 

 the appearance of the special qualities possessed 

 by a given set of chromosomes themselves? 

 Surely not a second set of chromosomes — i.e., 

 similar physiological units of a lower order? 

 Evidently these would require a third set of 

 determinants, and so on ad infinitum, like the 

 fleas in Swift's epigram. But the facts of physical 

 science forbid any such regressus since limits to 

 divisibility are set by the atomic or electronic 

 constitution of matter."^* 



Atomic physics enables a refinement of definite 

 concepts to a degree until recently deemed im- 

 possible. But the thorough establishment of modern 

 atomic physics is of most recent date. As yet com- 

 paratively few persons are thoroughly conversant 

 with the facts of the new atomic physics and the labors 

 (including the early labors of Kaufmann, Laue, other 



" Journal of Philosophy, Psychology, and Scientific Methods, XVII, 38. 



