x] of the Nervous System. 295 



" and after fifty or even after a hundred years, if a man lives so 

 " long, remain vivid and clear." 



He then goes on to discuss the question whether any 

 particular parts of the brain, by a special privilege, function 

 as the seat of sensation and the source of movement. " In all 

 " cases we have shewn that the impressions of the senses are 

 " carried to the brain, and the cause of movement is conveyed 

 " thence through the nerves to the muscles of the whole body. 

 " But learned men, even those of the school of Galen as well 

 "as those of recent years, have suspected that the power of 

 " receiving feeling and of exciting movement was not alike in 

 "particular parts of the brain, and that the whole brain was 

 "not necessary for the full development of sensations." He 

 discusses this question, using as tests the phenomena of disease 

 and the results of experiments on animals. Guided by these, 

 he rejects the view held by Willis and others that the 

 corpora striata serve as the seat of sensation and the source of 

 movement, as well as the view that the cerebellum is essential 

 to life. In the light of our modern knowledge it is most 

 interesting to follow this physiologist of a hundred and fifty 

 years ago striving to find his way along the tangled path 

 presented by the nervous phenomena resulting from disease 

 or from experimental interference. 



He then passes on to what he calls 'conjectures.' The 

 views which he has " so far put forward have been based on the 

 " evidence of the senses, and if we have erred the error has lain 

 "in the experiment. This fault however can readily be mended 

 " since by simple repetition it can be ascertained whether we 

 " are really following nature's lead or have wandered from the 

 " truth, led astray by the fewness of the experiments or by some 

 " mistake in carrying them out. It is not equally easy to keep 

 " oneself from error in the matters which have now to be dis- 

 " cussed. Very little of what follows is based on the evidence of 

 "the senses, but is reached by probable arguments gathered 

 " from all manner of sources, and these while they are strong 

 " enough to furnish ourselves with the hope of truth, do not 

 " possess that certainty which will carry conviction to the mind 

 " of others." 



