Meyer, Data of Modem Neurology. 297 



the results of the action of segmental efferent neurones only ; 

 and subjectively perhaps only the action of psychical elements in 

 the chain with their connections with the apparatus of speech, 

 etc.? This seems fairly probable. We do not know * how ' 

 we contract muscles although we may know what we ' do ' ; 

 nor do we know how the segment feels ; we only know ' how ' 

 the * personal, ' or psychical, part of the chain reacts to what 

 is going on in the segment. From the knowledge of these two 

 factors we build up the psychological concept of 'sensory- 

 motor ' mechanisms. 



It would lead us too far, were we to analyze here the 

 methods of reasoning of neuropathology. What has been said 

 must be sufficient to show that the connection of clinical with 

 anatomical neuropathology has many difficulties apart from the 

 difficulty of direct observation. The interpretation of findings 

 is, indeed, very difficult as soon as one leaves the beaten tracks 

 of the clinical parade-types. In current localization the great 

 questions are : peripheral, spinal, central or psychic for the 

 quantitive motor disorders ; cerebellar or * sensory ' for the 

 ataxias ; peripheral, spinal, central or psychic for the disor- 

 ders of sensation. For the parade forms of nervous diseases 

 these general types of localization miy be sufficient : but there 

 remain enough cases which will not fit, and enough diseases 

 which give rise to a flood of perhaps unnecessary literature, 

 simply because the localization spirit is poorly directed by the 

 spirit of faulty general pathology. The inefficiency lies not 

 in the desire for localization, but in the use of an exclusively 

 topograpJiical localization. 



The localization furnished with experiments of irritation or 

 destruction of parts of the nervous system — we called it the 

 scalpel-method — is roughly topographical. Now it lies in the 

 very nature of the plan of the nervous system given with the 

 views developed above that coarse morphological topography 

 must yield to, or at least accept, the assistance of functional lo- 

 calization. This, we have seen, drops the divisions of the ner- 

 vous system into brain, medulla oblongata, spinal cord and peri- 



