64 THE DATA OF BIOLOGY. 



merous and more marked. So that though organic change 

 is not rigorously distinguished from inorganic change by 

 presenting successive phases though some inanimate objects, 

 as watches, display phases of change both quick and nu 

 merous though all objects are ever undergoing change of 

 some kind, visible or invisible though there is scarcely any 

 object which does not, in the lapse of time, undergo a con 

 siderable amount of change that is fairly divisible into phases ; 

 yet, vital change so greatly exceeds other change in its dis 

 play of varying phases, that we may consider this as prac 

 tically one of its characteristics. Life, then, as thus roughly 

 differentiated, may be regarded as change presenting succes 

 sive phases ; or otherwise, as a series of changes. And it 

 should be observed, as a fact in harmony with this concep 

 tion, that the higher the life the more conspicuous the varia 

 tions. On comparing inferior with superior organisms, these 

 last will be seen to display more rapid changes, or a more 

 lengthened series of them, or both. 



Contemplating afresh our two typical phenomena, we 

 may see that vital change is further distinguished from non- 

 vital change, by being made up of many simultaneous changes. 

 Assimilation is not simply a series of actions, but includes 

 many actions going on together. During mastication the 

 stomach is busy with the food already swallowed ; on which 

 it is both pouring out solvent fluids and expending muscular 

 efforts. While the stomach is still active, the intestines are 

 performing their secretive, contractile, and absorbent func 

 tions ; and at the same time that one meal is being digested, 

 the nutriment obtained from a previous Tneal is undergoing 

 that transformation into tissue which constitutes the final act 

 of assimilation. So also is it, in a certain sense, with mental 

 changes. Though the states of consciousness which make up 

 an argument occur in series, yet, as each of these states is 

 complex implies the simultaneous excitement of those many 

 faculties by which the perception of any object or relation 

 has been effected ; it is obvious that each such change in 



