CORRESPONDENCE BETWEEN LIFE AND ITS CIRCUMSTANCES. 97 



of atomic arrangement. Outside there is another thermal 

 change; inside there is another change of atomic arrange- 

 ment. But subtle as is the dependence of each internal upon 

 each external change, the connexion between them does not, 

 in the abstract, differ from the connexion between the motion 

 of a straw and the motion of the wind that disturbs it. In 

 either case a change produces a change, and there it ends. 

 The alteration wrought by some environing agency on this or 

 any other inanimate object, does not tend to induce in it a 

 secondary alteration which anticipates some secondary altera- 

 tion in the environment. But in every living body there is 

 a tendency towards secondary alterations of this nature ; and 

 it is in their production that the correspondence consists. 

 The difference may be best expressed by symbols. Let A be 

 a change in the environment, and B some resulting change 

 in an inorganic mass. Then A having produced B, the 

 action ceases. Though the change A in the environment is 

 followed by some consequent change a in it; no parallel 

 sequence in the inorganic mass simultaneously generates in it 

 some change h that has reference to the change a. But if 

 we take a living body of the requisite organization, and let 

 the change A impress on it some change C; then, while in 

 the environment A is occasioning a, in the living body C will 

 be occasioning c; of which a and c will show a certain con- 

 cord in time, place, or intensity. And while it is i?i the 

 continuous production of such concords or correspondences 

 that Life consists, it is hy the continuous production of them 

 that Life is maintained. 



The further criticism to be expected concerns certain 

 verbal imperfections in the definition, which it seems impos- 

 sible to avoid. It may fairly be urged that the word corre- 

 spondence will not include, without straining, the various 

 relations to be expressed by it. It may be asked : — How can 

 the continuous processes of assimilation and respiration corre- 

 spond with the co-existence of food and oxygen in the environ- 

 ment ? or again : — How can the act of secreting some def en- 



