126 SCIENCE PROGRESS. 



is to be yes, an epigenetic explanation is inconceivable, 

 and an evolutionary theory is necessary. But an evolu- 

 tionary theory carries with it consequences which when 

 followed up soon land us in the inconceivable. 



Whitman has concluded his article with a quotation from 

 an essay by Huxley. I will conclude mine by another 

 quotation from the same essay, which I humbly recommend 

 to those who, styling themselves morphologists, are much 

 given to philosophical speculation. 



" Physiology and ontology are two sciences which cannot 

 be kept too carefully apart ; there may be such entities as 

 causes, powers and forces, but they are the subjects of the 

 latter, not of the former, science, in which their assumption 

 has hitherto been a mere gaudy cloak for ignorance. For 

 us physiology is but a branch of the humble philosophy of 

 facts, and when it has ascertained the phenomena presented 

 by living things and their order its powers are exhausted. 

 If cause, power, force, mean anything but convenient names 

 for a mode of association of facts, physiology is powerless to 

 reach them " — a powerlessness, I may add, which is in no 

 way diminished by the assumption of any number of ultimate 

 bodies in which the forces may reside. I beg to submit, in 

 conclusion, that the ascertained phenomena of develop- 

 ment presented by living beings and their order may 

 be expressed by epigenesis, and cannot be expressed by 

 evolution in its narrower sense. It is possible that, when 

 more facts are ascertained, epigenesis will have to give 

 way, though this does not seem to me probable ; but the re- 

 quirements of a theory are not ascertained facts, and must 

 not be thought to have invalidated a useful and substantial 

 doctrine. 



G. C. Bourne. 



