88 THE CRITERIA OF LIVINGNESS 



investigators claim for the organism a unique power of re- 

 tarding the universal tendency of energy to sink into unavail- 

 able form, in other words, of evading, in some measure, the 

 second law of thermodynamics. 



(2) If a piece of organism be ground up in a mortar and 

 the expressed juice poured into a vessel, a process of metab- 

 olism is sometimes observable similar to that which occurs 

 in the living body. Every one knows that pepsin may be 

 bought at the chemist's, and used to digest a shred of beef 

 in a test-tube. It is true that neither the ferment nor the 

 proteid can as yet be synthesised artificially, but this may 

 be only a question of time and ingenuity. We cannot dog- 

 matise as to the limits of mimicking in a test-tube what 

 occurs normally in an organism, and if the reaction be 

 mimicked, then there is nothing characteristically vital about 

 it, any more than there is about organic substances like 

 sugar and indigo which used to be regarded as producible 

 in organisms only. But the point is that in the living 

 organism the process in question is a link in a concatenated 

 series which makes for self-repair and continuance. The 

 essential secret of living is in the correlation which secures 

 persistence amid change. 



(3) If the -whole of a living organism, say a spinach 

 plant, were to be minced up quickly, no change of chemical 

 composition would necessarily occur for some little time, 

 but what exhibition would there be of the alleged funda- 

 mental characteristic of self-repair? It may be answered 

 that the mincing has destroyed the make-up of the organism, 

 that the living units of the body are in most cases adapted 

 for self-repair only in particular conditions, such as an 

 environment of other cells, in tho collocation which has been 

 abolished by the mincing. But while the power of self-repair 



