TRANSACTIONS OF SECTION I. 805 



iuqiibies, even when they were carried out with the safeguard of an adequate psychical 

 analysis of the phenomena which presented themselves, and this was not always 

 the case, sounded a very uncertain note, at least when they dealt with other than 

 simply motor effects. They were, moreover, not unfrequently in discord with 

 clinical experience. In general the conclusions which were arrived at through 

 them, save such as were based on the production of easily recognised and often 

 measurable movements, were regarded by many as conclusions of the kind which 

 could not be ignored, which demanded respectful attention, and yet which failed 

 to carry conviction. It seemed to be risking too much to trust too implicitly to 

 the apparent teaching of the results arrived at ; something appeared wanting to give 

 these their full validity, to explain their full and certain meaning by showing their 

 connection with what was known in other ways and by other methods. On the 

 other hand, during nearly all this time, in spite of the valuable results acquired by 

 the continually improving histological technique, by the degeneration method, and 

 by the developmental method, by the study of the periods of myelination, most of 

 us, at all events, were sitting down, as our forefathers had done, before the intricate 

 maze of encephalic structure, fascinated by its complexity, but wondering what it 

 all meant. Even when we attempted to thread our way through the relatively 

 simple tangle of the spinal cord, to expect that we should ever see our way so to 

 unravel out the strands of fibres, here thick, there thin, now twisting and turning, 

 and anon running straight, or so to set out in definite constellations the seeming 

 milky way of star-like cells, so to do this as to make the conformation of the cord 

 explain the performances of which it is capable, appeared to be something beyond 

 our reach. And when we passed from the cord to those cerebral structures the 

 even gross topography of wnich is the despair of the beginner in anatomical studies, 

 the multiple maze of grey and white matter seemed to frame itself into the letters 

 graven on the gateway of the city of Dis, and bid us leave all hope behind. 



What a change has come upon us during the past dozen years, and how great 

 is the hope of ultimate success which we have to-day. Into what at the meeting 

 at Montreal seemed a cloudy mass, in which most things were indistinct and 

 doubtful, and into which each man could read images of possible mechanisms 

 according as his fancy led, the method of Golgi has fallen like a clarifying drop, 

 and at the present moment we are watching with interest and delight how that 

 vague cloud is beginning to clear up and develop into a sharp and definite picture, 

 in which lines objectively distinct and saying one thing only reveal themselves more 

 and more. This is not the place to enter into details, and I will content myself 

 with pointing out as illustrative of my theme the progress which is being made in 

 our knowledge of how we hear and how sounds affect us. A dozen years ago we pos- 

 sessed experimental and clinical evidence which led us to believe that auditory 

 impulses sweeping up the auditory nerve became developed into auditory sensations 

 through events taking place in the temporo-sphenoidal convolution, and we had some 

 indications that as these passed upward through the lower and middle brain the 

 striae acusticse and the lateral fillet had some part to play. Beyond this we knew 

 but little. To-day we can with confidence construct a diagram which he who 

 runs can read, showing how the impulses undergoing a relay in the tuberculum 

 acusticum and accessory nucleus pass by the striae acusticae and trapezoid 

 fibres to the superior olive and trapezoid nucleus, and onwards by the lateral 

 fillet to the posterior corpus quadrageminum and to the cortex of the temporo- 

 sphenoidal convolution. And if much, very much, yet remains to be done even 

 in tracking out yet more exactly the path pursued by the impulses while they are 

 still undeveloped impulses, not as yet lit up with consciousness, and in understand- 

 ing the functional meaning of relays and apparently alternate routes, to say 

 nothing of the deeper problems of when and how the psychical element intervenes, 

 we feel that we have in our hands the clue by means of which we may hope to 

 trace out clearly the mechanisms by which, whether consciousness plays its part 

 or no, sounds affect so profoundly and so diversely the movements of the body, 

 and haply some time or other to tell, in a plain and exact way, the story of how 

 we hear. I have thus referred to hearing because the problems connected with 

 this seemed, thirteen years ago, so eminently obscure ; it appeared so pre-eminently 



