No. 606] 



BIOLOGICAL ENIGMAS 



327 



ern physico-chemical ideas to the problems of evolution 

 and heredity, which make up the heart of the biological 

 mystery. 



It has for some years been my conviction that the con- 

 ception of enzyme action, or of specific catalysis, provides 

 a definite, general solution for all of the fundamental bio- 

 logical enigmas: the mysteries of the origin of living 

 matter, of the source of variations, of the mechanism of 

 heredity and ontogeny, and of general organic regula- 

 tion.*^ In this conception I believe we can find a single, 

 synthetic answer to many, if not all, of the broad, out- 

 standing problems of theoretical biology. It is an answer, 

 moreover, which links these great biological phenomena 

 directly with molecular physics, and perfects the unity 

 not alone of biology, but of the whole system of physical 

 science, by suggesting that what we call life is funda- 

 mentally a product of catalytic laws acting in colloidal 

 systems of matter throughout the long periods of geologic 

 time. This view implies no absurd attempt to reduce 

 every element of vital activity to enzyme action, but it 

 does involve a reference of all such activity to some en- 

 zyme action, however distantly removed from present 

 activity in time or space, as a necessary first cause. Ca- 

 talysis is essentially a determinative relationship, and 

 the enzyme theory of life, as a general biological hypoth- 

 esis, would claim that all intra-vital or ''hereditary" de- 

 termination is, in the last analysis, catalytic. 



The conception of enzyme action is, of course, one with 

 which all biologists, including students of genetics, are 

 extremely familiar.^"^ Probably there is no student of 

 morphogenesis who would not consider it absurd to deny 

 that enz\Tnes play a very important role in individual 

 development. In a number of cases such participation 

 has been cleai-ly demonstrated by experiment, and the 

 suggestion that the germ-cell contains ''determiners" for 



