LIVING THINGS AND MACHINES 121 



What after all are these biophors and determin- 

 ants? Most biologists, it is not unfair to say, 

 utterly refuse to believe in their existence and even 

 their describer is obliged to admit that they cannot 

 be seen by the microscope or recognised by any kind 

 of objective test. 



They are not objects known to science, for 

 science only deals with observable facts. They are 

 the products of a luxuriant and highly-developed 

 scientific imagination and have been postulated by 

 Professor Weismann for the purpose of explaining 

 the phenomena of nature, and, inter alia, of disprov- 

 ing the existence of a vital force in the living 

 organism. In point of fact Professor Weismann 

 builds up an elaborate edifice of imagination, based 

 on no sufficient substratum of fact, and then says, 

 "This is how things may happen [and of course 

 it is possible that they may] and as a matter of 

 fact I have no doubt that this is how things do 

 happen and that being so there is no need for your 

 vitalistic theories ". To which it may be replied, 

 first, that there is no kind of evidence for the things 

 by which Professor Weismann explains the pheno- 

 mena of life, and, secondly, that if they were all as 

 clear and patent as the rails and sleepers on a rail- 

 way line they would no more explain the operations 

 of nature than those parts of the railway system 



