PROTOPLASM 47 



be active at one moment and relatively inactive at another, depending 

 upon its physical state {e.g., whether in solution or not) and the presence 

 of other substances with which to react. It is not a certain chemical 

 composition, but activity, that marks a substance as a part of the living 

 system. The system remaining after the supposed removal of all dis- 

 pensable materials would comprise many classes of substances, some of 

 which, notably water, carbon, and proteins, are probably essential in all 

 forms of protoplasm because of their peculiar properties. The fact that 

 these forms of protoplasm are almost innumerable suggests that the com- 

 ponents of the fundamental system must vary quantitatively, qualita- 

 tively, and in their type of structural organization within considerable 

 limits. 



In any case it should be evident, in spite of the special importance of 

 certain forms of matter, that it is not this or that component but the 

 organized system as a W'hole which lives. Steel is not a time-keeping 

 material, but it may be an important constituent of a time-keeping 

 system, such as a watch. Proteins are not living compounds, but they are 

 important constituents of living systems. That which is distinctively 

 biological inheres not merely in the several components but in their 

 unique integration and the consequent peculiar action of the organized 

 system as a whole. The action of the whole can be said to be a sum of the 

 action of the parts only when it is remembered that the parts act as they 

 do because of their position in the whole. Hence a true conception of 

 the organism can be approached only when analysis into physico-chemical 

 components is followed by resynthesis into a biological whole. ^^ 



We may go a step farther and point out that the organism is not to be 

 sharply set apart from the environment. The two are so inseparably 

 interlocked that they must be conceived as a single integrated system 

 whose orderly operation is necessary to life.^^ Thus life is largely a rela- 

 tion or adjustment between the properties of the organism and those of 

 the environment (Brooks, 1889), or, as Herbert Spencer put it, a "con- 

 tinuous adjustment of internal relations to external relations. " 



"See J. A. Thomson (1920), C. Lloyd Morgan (1923), Jennings (1927), Russell 

 (1930), and Gray (1931). 



'^ For discussions of this point, see Jennings (1924), Sharp (1925), and Carrel 

 (1931). 



