Section IX. 

 General Summary and Conclusion. 



Special problems relative to the several parts of the 

 brain have already been iiscussei in the foregoing pages; flhile 

 summaries have been plaoei at the close of each of the sections. 

 There yet remain for consicieration a fe« topics of more general 

 scope gro/»ing out of the study as a /?hole. Before proceeding 

 to these questions, ho/vever, it will be desirable to review 

 briefly the most important results which have been obtained. 



1. General Summary. 



The Oblongata of Mustelus has become only slightly diver- 

 gent from the structural plan of the primitive neural tube. 



The ventral cornu of the spinal cord is oontinued into 

 the oblongata as the nucleus of the VI nerve, and as the scat- 

 tered commissural and tract-neurones of the formatio reticularis. 



The viscero-sensory system has had annexed to it a complex 



of peripheral sense-organs. The communis system -.vhich results 



from this union is represented by components of the VII, IX, 



and X nerves. The lobus vagi is the centre of the system. 



(141) 



