70 THE DATA OF BIOLOGY. 



geneous changes rather than to the definiteness of their 

 combination. Just as it is not so much its chemical elements 

 which constitute an organism, as it is the arrangement of 

 them into special tissues and organs ; so it is not so much its 

 heterogeneous changes which constitute Life, as it is the de- 

 finite combination of them. Observe what it is that ceases 

 when life ceases. In a dead body there are going on hetero- 

 geneous changes, both simultaneous and successive. What 

 then has disappeared? The definite combination has dis- 

 appeared. Mark, too, that however heterogeneous the simul- 

 taneous and successive changes exhibited by an inorganic 

 object, as a volcano, we much less tend to think of it as 

 living, than we do a watch or a steam-engine, which,, though 

 displaying homogeneous changes, displays them definitely 

 combined. So dominant an element is this in our idea of 

 Life, that even when an object is motionless, yet, if its parts 

 be definitely combined, we conclude either that it has had 

 life, or has been made by something having life. Thus then, 

 we conclude that Life is the definite combination of hetero- 

 geneous changes, both simultaneous and successive. 



26. Such is the conception at which we arrive without 

 changing our stand-point. It is, however, an incomplete 

 conception. This ultimate formula (which is to a consider- 

 able extent identical with one above given "the co-ordina- 

 tion of actions ; " seeing that " definite combination " is 

 synonymous with " co-ordination," and " changes both si- 

 multaneous and successive" are comprehended under the 

 term " actions ; '' but which differs from it in specifying the 

 fact, that the actions or changes are " heterogeneous ") this 

 ultimate formula, I say, is after all but proximately correct. 

 It is true that it does not fail by including the growth of 

 a crystal ; for the successive changes this implies cannot be 

 called heterogeneous. It is true that the action of a galvanic 

 battery is not comprised in it ; since here, too, heterogeneity 

 is not exhibited by the successive changes. It is true that by 



