THE BEGINNINGS OF LIFE. 67 



reveal themselves in the form of heat. The pre-exist- 

 ing force is itself the cause of the change of constitution 

 which results in the new manifestations. 



And, similarly, we have the most perfect right to 

 expect that, when a physical force gives rise to any 

 one of the modes of vital force, what takes place is 

 not so much a direct conversion or transmutation of 

 the force itself, but rather that the physical force 

 expends itself in bringing about new collocations of 

 matter either in converting non-living into living 

 matter, or in altering the molecular constitution of 

 matter which is already alive. The properties of this 

 matter being what we call c vital ' properties, it may be 

 said that the physical force has been transmuted into 

 vital force. Only when understood in this sense, are 

 the words c conversion ' or c transmutation ' suitable for 

 the expression of what really occurs. The almost ne- 

 cessary use of these terms has, we think, nevertheless 

 tended to foster an erroneous impression, which has 

 exercised its misleading influence by causing certain 

 physiologists to suppose that a special c vital force ' is 

 needed to effect the transmutation of incident physical 

 forces within the bodies of living organisms. In reality, 

 no special force is in the least needed to do the work 

 of conversion. Any pre-existing physical force, acting 

 upon an organism, expends itself in producing those 

 molecular re- arrangements which, with others, contri- 

 bute to enable the organism to carry on its so-called 

 c vital ' processes. If the doctrine of the Correlation 



F 2, 



