'76 The Unity of the Organism 



or in both, are perforce the ones who think most in terms 

 of the doctrine of evolution, and whose undertakings are 

 most guided and fashioned by evolutionary conceptions : 

 How and where and under what influences did these organ- 

 isms, these organs and tissues have their beginnings and 

 undergo development? So it happens that when a zoologist, 

 for example, is confronted with the vast array of chemical 

 compounds which his co-workers in the chemical laboratories 

 have made known, he is bound to extend to them his usual 

 string of queries. No matter how much information he is 

 given about the molecular construction, the solubility, the 

 reactions, the methods of laborator^^ production, of organic 

 compounds, he can be in no wise satisfied until he has been 

 told something about their original source, their way of get- 

 ting into existence, not only in the individual organisms but 

 also in the race. Many physiologists on the other hand, and 

 also it must be confessed, a considerable number of modern 

 botanists and zoologists, are very little concerned Avith such 

 questions. In fact it seems as though the evolution doctrine 

 had not made the slightest impression on many biologists 

 animated by the chemico-physiological spirit, so far as cjon- 

 cerns their attitude toward their special problems. These 

 students appear to "take" the substances they deal with as 

 things without beginnings, as eternally existent, or as com- 

 ing into being "by free grace," in some such way as pre- 

 Darwinian naturalists "took" their species. We had oc- 

 casion to refer at some length to a similar un-evolutionary 

 character of elementalist biology in a preceding chapter. 



The question of how far such an attitude is due to the 

 fact that physics is preeminently not an evolutionary science 

 is one of great interest, both practical and theoretical. The 

 very basal conception of modern physics, that of Matter and 

 Energy as the only real things (as in the quotation from 

 Watson : ". . . in the pliysical universe there are only two 

 classes of things ; to these the names Matter and Energy are 



