284 THEORETICAL BIOLOGY 



However the actual process may one day appear to the 

 eye of the observer who succeeds in penetrating the detail 

 of what goes on in the brain, one thing is certain — it will 

 occur in the forms familiar to us, of change of shape 

 and transference of excitation in nervous structures. The 

 arena in which the phenomena we expect to find must take 

 place is already so narrowed down that we need look for no 

 sort of sensational surprises. Everything will appear to pro- 

 ceed quite mechanically ; the super-mechanical invasions will 

 never come to be appreciated by our senses. The only thing 

 that we shall be able to show is the coming in of an auto- 

 matic rhythm in the bridge-forming — a kind of self-active 

 " Bahnung," if I may use Erner's term. 



It must be kept in mind that the impulse-melody is a 

 completely automatic process, which belongs to the subject 

 alone ; and while it can be excited by external circumstances, 

 it can never be formed by these. The capacity of responding, 

 now to one melody, now to another, is limited in the case of 

 each subject. One may play a certain sequence of notes as 

 often as one likes to an unmusical person ; he will not be able 

 to construct a melody therefrom. The same holds good of 

 optical capacity. There are only a few men so artistically 

 gifted that in them other than quite primitive melodies of 

 direction-signs sound forth, just sufficing for recognition of 

 the necessary objects. 



From this it follows that the power to form new impulse- 

 sequences through so-called " learning " is restricted. For 

 each creature there is a certain extent of learning power 

 (very different in different individuals) marked out at the 

 beginning. It depends on the individual whether he knows 

 how to exploit this to the full. 



