590 



PSYCHOLOGY. 



direction ; why, for example, we cannot say the alphabet 

 backward, and why, although S** discharges into S*', there 

 is no tendency for S" to discharge into S^, or at least no 

 more than for it to discharge into S".* The first-formed 

 paths had, according to the principles which we invoked, 

 to run from cells that had just discharged to those that 

 were discharging ; and now, to get currents to run the other 

 way, we must go through a new learning of our letters with 

 their order reversed. There will then be two sets of asso- 

 ciation-pathways, either of them possible, between the sen- 

 sible cells. I represent them in Fig, 91, leaving out the 

 motor features for simplicity's sake. The dotted lines are 

 the paths in the backward direction, newly organized from 



Fig. 91. 



the reception by the ear of the letters in the order C B A. 

 The same principles will explain the formation of new 

 paths successively concatenated to no matter how great an 

 extent, but it would obviousl}^ be folly to pretend to illus- 

 trate by more intricate examples. I will therefore only 

 bring back the case of the child and flame (Vol. I. p. 25), to 

 show how easily it admits of explanation as a * purely cortical 

 transaction ' [ibid. p. 80). The sight of the flame stimu- 

 lates the cortical centre S' which discharges by an instinc- 

 tive reflex path into the centre M' for the grasping-mo ve- 



* Even as the proofs of these pages are passing through my hands, I 

 receive Heft 2 of the Zeitschrift ftlr Psychologie u. Physiologie der Sin- 

 nesorgane, in which the irrepressible young Milnsterberg publishes experi- 

 ments to show that there is no association between successive ideas, 

 apart from intervening movements. As my explanations have assumed that 

 an earlier excited sensory cell drains a later one, his experiments and infer- 

 ences would, if sound, upset all my hypotheses. I therefore can (at this 

 late moment) only refer the reader to Herr M.'s article, hoping to review 

 the subject again myself in another place. 



