96 THE DATA OF BIOLOGY. 



prey requires a special combination of subjective actions, 

 fitted in degree and succession to overcome a group of objec- 

 tive ones. And so with those countless automatic processes 

 constituting instincts. 



In the highest order of vital changes the same fact is 

 equally manifest. The empirical generalization that guides 

 the farmer in his rotation of crops, serves to bring his actions 

 into concord with certain of the actions going on in plants 

 and soil. The rational deductions of the educated navigator 

 who calculates his position at sea, form a series of mental 

 acts by which his proceedings are conformed to surrounding 

 circumstances. Alike in the simplest inferences of the child 

 and the most complex ones of the man of science, we find a 

 correspondence between simultaneous and successive changes 

 in the organism, and co-existences and sequences in its en- 

 vironment. 



§ 29. This general formula which thus includes the lowest 

 vegetal processes along with the highest manifestations of 

 human intelligence, will perhaps call forth some criticisms 

 which it is desirable here to meet. 



It may be thought that there are still a few inorganic 

 actions included in the definition; as, for example, that dis- 

 played by the mis-named storm-glass. The feathery crystal- 

 lization which, on a certain change of temperature, takes 

 place in its contained solution, and which afterwards dis- 

 solves to reappear in new forms under new conditions, may 

 be held to present simultaneous and successive changes that 

 are to some extent heterogeneous, that occur with some 

 definiteness of combination, and, above all, occur in apparent 

 correspondence with external changes. In this case vegetal 

 life is simulated 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 not 

 a correspondence at all, in the proper sense of the word. Out- 

 side there is a thermal change; inside there is a change 



