FACTS AND FINDINGS 45 



from a belief that in the physicochemical explanation lies 

 the only mode of approach to an understanding of life 

 itself acceptable to the modern man. 



Let us then, at this point, try to find what modern biol- 

 ogists consider the most fundamental problems of the day. 



Again there is practical unanimity. 



1. The nature of life. That is, does living organic sub- 

 stance differ from the inorganic? While this problem is 

 far from being solved, it seems that the recent work on 

 bacteriophages and the filterable viruses is pushing our 

 horizon to a much lower level. 



2. The discovery and constitution of protoplasm, and 

 its manner of operation. 



3. The problem of the causes of variation, which may 

 in turn be stated as the mechanism of differentiation and 

 the mechanism of evolution. 



4. Cancer research. Cancer is ravaging humanity con- 

 tinuously to a greater extent, and practically nothing is 

 known of either its origin, its control, or its cure. 



5. The relation of genetics and environment. Important, 

 because so many human problems are affected by genetics, 

 such as disease, sociology, etc. 



6. Disease. Is its predisposition really hereditary or 

 is it environmental ? Is any defect really hereditary, or is 

 it induced by environment ? 



7. Criminality. Is it an heredity defect, or is it environ- 

 mental in its origin? These are decidedly important 

 human problems. Even immigration is affected by the 

 answer. 



