x] of the Nervous System. 281 



results in relation to glands and to muscle, the story of the 

 progress of physiology of the nervous system in the times 

 coming after him, would, we may well think, have been very 

 different from that which we have to record it actually is. 

 But it was not to be. Stensen as we have seen was drawn to 

 other things, and there was no one to take his place. After 

 Willis a long period followed before anyone took up again the 

 problems with which he bad busied himself. Many valuable 

 additions continued, it is true, to be made to the anatomy of 

 the brain, slowly and from time to time ; but for a long while 

 no one took up the physiological inquiry with the fervour 

 which had marked the middle of the seventeenth century. 

 In tracing out the progress of science the trend of investi- 

 gation is found to vary from time to time ; at one period men's 

 minds are intently occupied with one set of problems, and at 

 another period these seem to be without cause almost wholly 

 neglected. But, even allowing for such an ill-understood 

 rhythm of inquiry, it is , difficult to resist the thought that 

 the absence of research of which we are speaking was in part 

 at least due to the sterilizing influence of Stahl's animistic 

 doctrines. 



During the eighteenth century, however, one remarkable 

 advancement of knowledge was made, which, though it con- 

 cerned not the functions of the brain proper, but the relations 

 of the functions of nerves to those of muscle, had a remarkable 

 influence over the whole of nervous physiology. This was the 

 chief work of the great Haller, and to this we must now turn. 

 In order, however, to appreciate the true value of Haller's 

 labours it will be necessary even at the risk of some recapitu- 

 lation to pass in review the various views put forward from 

 time to time concerning the action of nerves, and the relation 

 of that action to muscular movement. 



In an early lecture I spoke of Borelli's ideas concerning 

 muscular contraction and said a few words about his conception 

 of nervous action. I must now return to these, especially the 

 latter, and dwell upon some further details. 



Borelli, as we saw, took a distinctly physical view of 

 nervous action. To him the animal spirits were known as a 



