1 84 THE BEGINNINGS OF LIFE. 



it may be consumed in the work of secretion. But it 

 must also be remembered that portions of such liberated 

 motion may be consumed in carrying on the work of 

 nutrition and growth that is, in carrying on those acts 

 by which the matter of the organism is either renovated 

 or increased in quantity, with or without an increase in 

 the complexity of its structure. Similar molecular ener- 

 gies are also to a less extent set free by changes in 

 the active or functioning matter itself since all action 

 implies more or less of alteration in the molecular 

 structure of the substance which manifests it. 



Thus, whilst one portion of the assimilated food is 

 being decomposed, another is being simultaneously ele- 

 vated in the scale of complexity, and is fashioned into 

 the likeness of the matter to whose influence it is 

 exposed. Molecular movements of a special kind are 

 constantly taking place in each growing tissue, and the 

 molecules of adjacent organic matter contained in the 

 nutritive fluids with which they are brought into con- 

 tact, seem (whilst obeying an inherent tendency to 

 enter into c living ' combinations) to be coerced to fall 

 into living matter similar to that of the tissue itself 1 . 

 That is to say, whilst living matter is formed as a 

 result of an inherent tendency of the food molecules 

 to enter into such modes of combination, the peculiar 

 kind of living matter which is produced is attributable 

 to the influence of that with which it comes into 



1 See remarks concerning the assimilating processes carried on in an 

 Amoeba, p. 132. 



