ADAPTATION 171 



a state of functioning must therefore have been disturbed ; 

 but as functioning itself, at least in plants, certainly stands 

 in close relations to the medium, it follows that all adapta- 

 tions are in the last resort connected with those factors of 

 the medium which affect functioning. In being correctives 

 to the disturbances of functioning they become correctives 

 to the disturbing factors themselves. 



But again, the question seems to arise whether these 

 factors of the medium, when they provoke an adaptation 

 by some change that is followed by functional disturbance, 

 do so in the capacity of " causes ''' or of " means," and so 

 it might seem that we have not gained very much so far 

 by our analysis. The reproach, however, would not be quite 

 justified, it seems to me : we indeed have gained a new 

 sort of analytical concept, in the realm of causal concepts 

 in general, by clearly stating the point that adaptations are 

 related directly to functionality, and only indirectly, through 

 functionality, to external changes. By the aid of this logical 

 formulation we now are entitled to apply the term " cause," 

 in our restricted sense of the word, to every change of the 

 medium which is followed by any sort of adaptation in 

 regard to itself. Our definition stated that a " cause " is 

 any one of the sum of necessary factors from without that 

 accounts either for the localisation or for the specification 

 of the effect, and the definition holds very well in this 

 case. Indeed, the specification of the effect is determined 

 by the outside factor in every case of an adaptation to it, 

 by the mere fact of its being a specific adaptation to this 

 specific factor. 



We must not forget that in this chapter we are not 

 studying real individual morphogenesis as the realisation 



