18 S. BENT RUSSELL 



e = Unknown exponent 



a & b = Unknown constants 

 Fi = Discharge through the given channel 

 FT = Discharge through all channels 

 Our present capacity is then from premises 2, 3 and 



Ci=CP + CL + a— bt e 

 and from premise 6 we have 



Fi Ci 



FT CT 



Having now a conception of how the susceptibility of a 

 nervous channel will increase with each discharge and decrease 

 with disuse, let us take up the problem of inhibition again. 

 We will now modify our diagram so as to give this (Figure 002) : 



S2 SI 



~— Ml 



M2 



Figure 002 



As before, Si, Mi and S2, M2 are channels of good conduc- 

 tivity. The median channel Si, S2, x, M2 is one originally of 

 low conductivity. Now let the environment be such that the 

 movement Mi habitually produces the sensation S2. 



From our premises we see that at each experience the sus- 

 ceptibility of channel Si, S2, x, M2 is increased because its 

 first discharge is followed quickly by a second. It is evident 

 that the median channel w r ill, after repeated experiences, become 

 of high conductivity so that eventually the sensation Si will be 

 followed either by movement M2 or at least by a prevention of 

 Mi which is inhibition, as the movements are opposed. 



We now see how experience can develop the weak channel 

 faster than the strong one. This case may be considered as 

 one of converging nervous channels. 



To illustrate the case : the sight of the fire excites a forward 

 movement, Mi. The sharp pain of the burn excites a back- 



