56 



sciousness." 1 "Thus we see," Romanes concludes, "so far as 

 we can ever hope to see, how conscious action gradually arises 

 out of reflex." 2 And in a later portion of the work, conscious- 

 ness is spoken of as being "but an adjunct which arises when 

 the physical processes owing to the infrequency of repetition, 

 complexity of operation, or other causes, involve what I have 

 before called ganglionic friction." 3 



In the cases of memory and association, the relation would 

 be as follows: "Memory on its physiological side can only 

 mean that a nervous discharge, having once taken place along 

 a certain route, leaves behind it a molecular change, more or 

 less permanent, such that when another discharge afterwards 

 proceeds along the same route, it finds, as it were, the foot- 

 prints of its predecessor. * * * In all but the absence of a 

 mental constituent the nerve centre concerned remembers the 

 previous occurrence of its own discharges; these discharges 

 have left behind them an impress upon the structure of the 

 ganglion just the same in kind as that which, when it has 

 taken place in the structure of the cerebral hemispheres, we 

 recognize on its obverse side as an impress of memory." 4 



The same argument is applied on the physiological side of 

 the 'association of ideas'. "In the complex structures of the 

 cerebral hemispheres one nervous arc (fibres, cells, fibres) is 

 connected with another nervous arc, and this with another, 

 almost ad infinitum. * * * The more frequently a nervous dis- 

 charge takes place through a given group of nervous arcs, the 

 more easy will it be for subsequent discharges to take place 

 along the same routes these routes having been rendered 

 more permeable to the passage of subsequent discharges. And 

 now a very little reflection will show that in this physiological 

 principle we no doubt have the objective side of the psycho- 

 logical principle of the association of ideas. For it may be 

 granted that a series of discharges taking place through the 

 same group of nervous arcs will always be attended with the 

 occurrence of ideas. * * * The tendency of ideas to recur in 

 the same order as that in which they have previously occurred, 

 is purely a psychological expression of the physiological fact 

 that lines of discharge become more and more permeable by 

 use." 5 



We may finally illustrate the operation of this principle 

 by reference to the phenomena of choice and purpose. The 



O.C. p. 74. 

 'Ibid. 



3 O.C. p. 113. 

 4 O.C. p. 35. 

 6 O.C p. 37. 



