106 THE DATA OF BIOLOGY. 



•vironment that has been growing ever more involved. Thus, 

 speaking generally, it is clear that those relations in the en- 

 vironment to which relations in the organism must corre- 

 spond, themselves increase in number and intricacy as the 

 life assumes a higher form. 



§ 34. To make yet more manifest the fact that the degree 

 of life varies as the degree of correspondence, let me here 

 point out, that those other distinctions successively noted 

 when contrasting vital changes with non-vital changes, are 

 all implied in this last distinction — their correspondence 

 with external co-existences and sequences; and further, that 

 the increasing fulfilment of those other distinctions which 

 we found to accompany increasing life, is involved in the 

 increasing fulfilment of this last distinction. We saw that 

 living organisms are characterized by successive changes, and 

 that as the life becomes higher, the successive changes be- 

 come more numerous. Well, the environment is full of 

 successive changes, and the greater the correspondence, the 

 greater must be the number of successive changes in the 

 organism. We saw that life presents simultaneous changes, 

 and that the more elevated it is, the more marked the multi- 

 plicity of them. Well, besides countless co-existences in the 

 environment, there are often many changes occurring in it at 

 the same moment; and hence increased correspondence with 

 it implies in the organism an increased display of simul- 

 taneous changes. Similarly with the heterogeneity of the 

 changes. In the environment the relations are very varied 

 in their kinds, and hence, as the organic actions come more 

 and more into correspondence with them, they too must 

 become very varied in their kinds. So again is it even 

 with definiteness of combination. As the most important 

 surrounding changes with which each animal has to deal, are 

 the definitely-combined clianges exhibited by other animals, 

 whether prey or enemies, it results that definiteness of com- 

 bination must be a general characteristic of the internal ones 



