554 SCIENCE PROGRESS 



It is theoretically possible that both these fundamental 

 properties of living matter came to be found in it because 

 they were inherent in the pre-existing non-living matter from 

 which the living may be supposed to have been evolved. 

 Similarly for the power of transmuting energy, a property 

 notoriously not confined to livingness. 



Nor does anything said here contradict the belief that 

 affectability, functional inertia, and the transmutation of 

 energy are primary or fundamental properties, while the last 

 four are secondary or derived. For instance, if living matter 

 had no affectability, it would be unaffected by the presence 

 of food material, and so would not respond to it in the direc- 

 tion of assimilating it. 



Recent physiological work has made us aware of a power 

 in living tissues to offer resistance to the so-called " physical 

 forces." We have been shown that the important function 

 of absorption of food from the intestine is not capable of being 

 explained by the laws of " physical " osmosis alone. The 

 " mechanism " of absorption is not mechanical in the sense 

 that it is the outcome of laws operative entirely in non-living 

 matter. Prof. Waymouth Reid has demonstrated that if the 

 living cells lining the alimentary canal be removed, the food 

 is absorbed less perfectly than before, although now it is of 

 course actually nearer to the blood which is ultimately to 

 receive it. Similarly, Prof. Gregor Brodie has proved that 

 in the kidney, merely physical forces, blood-pressure, etc., 

 will not account for the formation of the watery secretion of 

 that gland ; he is compelled to speak even of the water as 

 being vitally secreted. Dr. J. S. Haldane, of Oxford, asserts 

 that under certain conditions the living lining of the lung 

 acts, as regards the excretion of carbonic acid gas and the 

 intake of oxygen, in direct opposition to purely physical diffu- 

 sion. 



I have purposely not grounded the thesis of this paper on 

 the phenomena of consciousness. The existence of conscious- 

 ness is the supreme distinguishing feature between the living 

 and the non-living ; but our uncertainty as to the existence of 

 self-consciousness in the lower forms of life precludes us from 

 making dogmatic statements about its significance as a 

 differentia of livingness in every one of the types of living 

 matter. It seems safe to assume that consciousness does not 





