422 Action of the Genetic Material 



specific rate processes and quantities of products could be marked. 

 And all this would have to be attached in the proper order to a single 

 time coordinate. It might be possible, fulfilling Hersh's postulate (see 

 III 5 C), to derive differential equations that cover this entire setup. 

 But would such an equation contain any biological understanding of 

 the processes of genie action? I think tliat an exact knowledge of what 

 "stratification" signifies in known chemical and physical terms would 

 mean much more to the geneticist than a differential equation con- 

 taining all the general features of genie control of development. Here, 

 perhaps, lies the basic difference between biology and physics, a topic 

 so much and so differently discussed by theoretical biologists from 

 Driesch to Bertalanffi, by innumerable philosophers, and more re- 

 cently also by theoretical physicists like P. Jordan and Schrodinger. 

 At this point, however, I must draw the line for what, in my opinion, 

 or better, my intention, belongs to the subject matter of this book. 



