298 Journal of Comparative Neurology. 



pheral nervous system in favor of : segments plus supra-seg- 

 mental apparatus. 



We should have to write a book if we tried to discuss the 

 arrangements of the facts available in the entire neuropathology 

 on the ground of the concepts dictated by our discussion. We 

 cannot give more than a rough outline here. The neurone-the- 

 ory is only part of the whole concept. Recent investigations 

 have been turning around problems relatively immaterial for the 

 general point of view to be taken in neuropathology. Detail- 

 problems have dulled the interest in larger ones. Many stu- 

 dents are remarkably well informed on all the shades of the 

 'contact-theory,' but with the same effect which we all know to 

 come when histologists work only with oil-immersions and for- 

 get to get a broad frame for the details Avith the use of low 

 powers. 



We have seen that we get our neurological knowledge from 

 three clearly independent series of data. Our efforts go in the 

 direction of melting them into one, i. e. into an objective con- 

 ception of the nature and work of the nervous mechanisms. 

 The naive realism of 'common sense' achieves this correlation 

 very rapidly, usually in the sense of the center-theory. 'Wher- 

 ever you can destroy it isolately, there must be its center, and 

 in the center are the images etc.;' this is roughly expressed its 

 motto. 



I shall try to show how an uncritical use of this point of 

 view combined with a purely anatomical one leads to habits of 

 thought not altogether safe. Without entering on the polemics 

 concerning localization, we can state that the ' motor region ' 

 alone (Bastian) or the motor area plus the parietal (Starr) form 

 the principal part of the ordinary highest sensory motor me- 

 chanisms. The path usually given for a ' sensation ' is the one 

 represented in the plan of the brain as afferent cerebral. The 

 segmental afferent neurone sends a branch to the nucleus of Goll 

 or Burdach (the former in the case of a lumbar segment, the 

 latter in the case of the cervical) ; the impulse is communicated 

 there to elements of the fillet and from these to elements of the 

 radiation of the nucleus ventralis thalami. If this is correct we 



