119 



but tvto thalamic nuclei. One, the nucleic striti i^riaei, has 

 become isfined from the centr-il ^^r-iy mitt=»r for the reception 

 of f ibre-teminations, chiefly those of the trictus strio- 

 thalamicas from the striat'in; the axones of the nucle'is give 

 origin to the trictus thilano tectnlis. The other thnlamic 

 nucleus, the nucleus geniculatum, receives collateral branches 

 from optic fibres. It is wholly inferior to the tectum mesen- 

 cephali as an optic termination, but it represents the special- 

 ize! genicilate nuclei of higher forms. 



The two nuclei habenulae do not exhibit great disparity 

 in size. An olfactory tract, the tractus olfacto-habenularis, 

 terminates here; the neurones of the nuclei give origin to the 

 tractus habenalo-peduncilaris. 



The lobi inferiores are the seat of a crowded group of 

 neurones, and the lobes are thereby given a large size. A 

 neurone has a widely spreading dendritic top. Its axone branch- 

 es in a T-shaped manner. 



Supporting elements are strongly developed The neuroglia 

 is remarkable for the mat-like interlacing of its branches. 

 Spendymal fibres often ramify to a striking degree; they ex- 

 tend through the .Thole thickness of the neural tube. 



