CHAPTER VI. 



THE DEGREE OF LIFE VARIES AS THE DEGREE OP 

 CORRESPONDENCE. 



31. ALREADY it has been shown respecting each other 

 component of the foregoing definition, that the life is high in 

 proportion as that component is conspicuous; and it is now 

 to be remarked, that the same thing is especially true re- 

 specting this last component- the correspondence between 

 internal and external relations. It is manifest, a priori, that 

 since changes in the physical state of the environment, as 

 also of those mechanical actions and those variations of 

 available food which occur in it, are liable to stop the pro- 

 cesses going on in the organism; and since the adaptive 

 changes in the organism have the effects of directly or in- 

 directly counter-balancing these changes in the environ- 

 ment; it follows that the life of the organism will be short 

 or long, low or high, according to the extent to which changes 

 in the environment are met by corresponding changes in the 

 organism. Allowing a margin for perturbations, the life will 

 continue only while the correspondence continues; the com- 

 pleteness of the life will be proportionate to the complete- 

 ness of the correspondence; and the life will be perfect only 

 when the correspondence is perfect. Not to dwell in general 

 statements, however, let us contemplate this truth under its 

 concrete aspects. 



32. In life of the lowest order we find that only the most 

 prevalent co-existences and sequences in the environment, 

 8 101 



