THE BEGINNINGS OF LIFE. 185 



contact — whether we have to do with independent or- 

 ganisms, or with mere subordinate units entering into 

 the composition of the muscles, nerves, or glands of 

 some higher organism. 



Some of these views have been previously advocated 

 by others. Thus, Liebig has pointed out 1 that ' the 

 animal metamorphosis is itself a main cause of the 

 alterations which the food undergoes, and a determining 

 condition of the nutritive process.' And the depen- 

 dence of the phenomena of Life upon decomposition 

 has also been ably argued by Dr. Freke and A4r. Hinton. 

 The decomposing matter is supposed by them to render 

 active an amount of force which helps to give rise to 

 new living compounds 2. Our position, that during the 

 growth of organisms living matter is formed, partly in 

 obedience to natural tendencies possessed by certain 

 kinds of molecules to enter into such modes of com- 

 bination, and partly under the immediately fashioning 

 influence of the pre-existing living matter, will be 

 better understood after some additional words of ex- 

 planation. 



Liebig has frequently called attention to the fact 



^ See vol. i. p. 426. 



"^ Mr. Hinton says (' Life in Nature/ p. 238) : — ' As one example, let 

 us take the germination of the seed. Put into conditions which elicit 

 or permit the operation of the chemical affinities, it begins to decom- 

 pose. The downward or approximative motion thus arising, imparted 

 to other elements in the seed which are so constructed as to admit of 

 motion most readily in the opposite or vital direction, becomes in these 

 elements a motion of life or growth.' 



