THE SPECIFIC CHARACTERISTICS OF VITALITY 553 



described as specifically characteristic of it : when it had 

 acquired these it was alive. 



Functional endowment, therefore, and not the possession 

 of any " vital force," constitutes livingness. The desire of the 

 chemists to create living out of non-living matter is not hereby 

 ridiculed, neither is it pronounced impossible. But we must 

 be prepared beforehand to recognise this man-made living 

 matter whenever and wherever we may be privileged to see it. 

 Presumably it will be first presented to us in a test-tube. 

 How shall we know that it lives ? The biochemist says that 

 protoplasm is an irreversible colloidal hydrosol of emulsoid 

 constitution : excellent, but how may we know that this 

 hydrosol is alive ? Not from its conforming to the above 

 description, for matter entirely dead might still be so des- 

 cribed. By its " extreme complexity " ? No ; for again 

 extreme chemical complexity can characterise both non-living 

 and dead matter. By its possessing affectability, functional 

 inertia, and the power of transmuting energy ? Once more, no, 

 for all these three are possessed by certain lifeless substances. 

 Matter, whatever its origin, cannot be pronounced alive unless 

 it is capable of assimilating the unlike, of producing anti- 

 bodies, of reproducing itself and of undergoing spontaneously 

 a certain degree of morphological differentiation. 



These are the credentials of living matter as we find it in 

 the universe to-day ; matter, wherever it has arisen, which 

 possesses these four properties must be called alive. 



Some years ago I contended * that affectability and func- 

 tional inertia were the two fundamental properties of living 

 matter, and such indeed we must regard them. No kind of 

 matter which does not respond to a stimulus can be called 

 alive ; all matter which is alive can or may respond to a 

 stimulus, but affectability is shared by non-living matter. 

 Conversely, matter which was the everlasting plaything of 

 stimulation, which could not resist or be oblivious to certain 

 stimuli at certain times, would not be alive. It is of the essence 

 of livingness to disregard some stimuli, to prevent some re- 

 sponses, to set limits to activity, to act rhythmically and not 

 constantly or continually ; but insusceptibility to stimulus is 

 a property shared also by non-living matter. 



1 Fraser Harris, The Functional Inertia of Living Matter. London: Churchill, 

 1908. 



