THE DATA OF BIOLOGY. 



nniteness of combination, and, above all, occur in correspond- 

 ence with external changes. In this case vegetal life is sim- 

 ulated to a considerable extent ; but it is merely simulated. 

 The relation between the phenomena occurring in the storm- 

 glass and in the atmosphere respectively, is really not a cor- 

 respondence at all, in the proper sense of the word. Outside 

 there is a certain change ; inside there is a change of atomic 

 arrangement. Outside there is another certain change ; in^ 

 side there is another change of atomic arrangement. But 

 subtle as is the dependence of each internal upon each ex- 

 ternal 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 an inani- 

 mate object, does not tend to induce in it a secondary altera- 

 tion, that anticipates some secondary alteration in the en- 

 vironment. 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 dif- 

 ference 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 ac- 

 tion ceases. Though the change A in the environment, is 

 followed by some consequent change a in it ; no parallel se- 

 quence in the inorganic mass simultaneously generates in it 

 eorne change b 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 in the con- 

 tinuous production of such concords or correspondences that 

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

 Life is maintained. 



The further criticism that may be expected, concerns cer- 



