ORIGIN OF THE CEREBRAL NERVES. 479 



the olivary bodies, are continued through the cells of the latter, or by 

 tracts that still remain to be discovered, to the motor centres of origin 

 of the cerebral nerves. Deiters indeed considered the longitudinal 

 fasciculi of the crus cerebri connected with the olivary bodies to be a 

 prolongation of the posterior columns into the cerebrum. This view, 

 however, is by no means in accordance with the morphological 

 appearances, inasmuch as (p. 469) the fasciculi of the tegmental tract 

 penetrating the olivary body proceed from the centre of areas which, 

 in the form of the layers of the fillet and motor area, pass into the 

 antero-lateral tract of the spinal cord. Thus the idea of the local 

 distinctness of the centrifugal and centripetal conducting tracts in the 

 mosaic presented by the transverse section of these areas must be 

 entirely dropped if the relation of the inferior olivary body to the pro- 

 jection system in the sense of Deiters be accepted ; a conclusion 

 which requires more convincing arguments for its acceptance than 

 have hitherto been adduced in its favour. Keference will hereafter 

 be made to the possible significance of the larger scattered cells. 



ORIGIN OF THE CEREBRAL NERVES, FROM THE FIFTH TO THE 



TWELFTH. 



The system, of the cerebral peduncle (Hirnschenkelsystem) 

 undergoes diminution within the territory of interlacement of 

 the cerebellar peduncles (Durchflechtungs-gebietes der Klein- 

 hirnarme) to the extent of those fascicular portions which, 

 representing the musculature and the sensory surfaces of the 

 head, reach their terminus in the grey matter of the central 

 cavities of this portion of the brain. Their terminal masses at 

 the same time serve (the fasciculi increasing in number) as the 

 point of origin of the third link of the projection-system belong- 

 ing to them, i.e., the cerebral nerves, which has been already dis- 

 cussed in reference to the nucleus of the third and fourth nerves. 



Just as the columnar portions of the cerebral peduncle which 

 become the spinal cord, so also will the columnar portions which 

 represent the cerebral nerves, present a duplicity of course in 

 the anterior and posterior tracts of the cerebral peduncle, cor- 

 responding to their relations to consciousness on the one hand, 

 and to their reflectorial relations on the other. 



The areas in the mosaic of the transverse section, which 

 belong to the cerebral nerves, are still indeed unknown ; and 



