470 



THE XERVOUS SYSTEM. 



warrantable violence to terms in general use, and such a 

 change of nomenclature is quite inconsistent with the homo- 

 logy of the parts from a developmental point of view. The 

 optic peduncle exhibits three very distinct bundles of fibres, 

 which I shall term (i) the commissural fibres (m, p) ; (2) the 

 thalamic fibres (v), which include the oculo-olfactory bundle ; 

 and (3) the mesocephalic fibres (;;/), which form the greater 

 part of the optic peduncle. 



2. The Inner Medulla may be described as consisting of an 

 anterior medullary mass (ac], which I shall term the corpus 

 ovale, partially embraced behind by a concavo-convex lentiscus 



ft. 



'! 



I- 1'.. 6l. A lateral section of one of the Optic danglia : ac, anterior capsule; 

 f, middle capsule ; //, the Ux-nia ending in Cuccati's bundle and the posterior 

 commissure ; .^', annular region of the cortex ; /-', the corona ; ,^, posterior, and 

 .V 4 , anterior, cell groups ; in, fibres of the peduncle entering the mesocerebron ; 

 //ic, middle commissure of optic ganglia traversing the floor of the cavity of the 

 cerebron ; <>r, external medulla ; <>;/, chia-ima <>f optic nerve; />. posterior fibres 

 of the peduncle ; /v, posterior capsule ; //, retina ; ///, thalamic lobe ; r 1 , thala- 

 mic fibres of the optic peduncle entering the thalamic loU-. 



(pc) ; this is the posterior capsule of Viallanes. Between the 

 corpus ovale and the posterior capsule there is an intermediate 

 layer, which differs entirely from the posterior capsule and 

 corpus ovale. This I term the middle capsule (c). Many of 

 the fibres of the middle capsule enter the thalamic bundle of 

 the optic peduncle, and others are lost in the corpus ovale (ac) 

 and the lentiscus (pc}. They diverge radially at their outer 



