432 



THE BRAIN OF MAMMALS, BY TH. MEYNERT. 



rendered complete by the fact established by Arnold, of the 

 connection of the optic tract with the zonular layer of the optic 



Fig. 248. 

 J? 



Fig. 248. Transparent vertical transverse section of the thalamus 

 opticus and crus cerebri at the posterior boundary of the third ven- 

 tricle. M, The medulla of the hemispheres ; Th, the thalamus opticus; 

 Vz, the third ventricle, lined by the central grey matter belonging 

 to the internal surface of the optic thalamus ; H, the ganglion in 

 the peduncle of the pineal gland ; Cm, the centrum medianum of 

 Luys ; C, corpus geniculatum externum ; Nc, nucleus caudatus ; TT, 

 the tegmentum of the crus cerebri ; EK, the red nucleus of the teg- 

 mentum, the medullary fasciculi of which issue from the medulla of 

 the hemispheres between uR and 8 ; P, the pes of the crus cerebri ; 

 S, the substantia nigra ; II, tractus opticus ; Sz, stratum zonale ; It, 

 the radiating fasciculi in the optic thalamus entering its upper layer 

 from the medulla of the hemispheres ; n JR, the radiating fasciculi in 

 the optic thalamus which penetrate its inferior layer from the tractus 

 opticus ; T', the concentric laminse medullares for the tegmentum of 

 the crus cerebri; H', the fasciculus from the ganglion of the peduncle 

 of the pineal gland for the tegmentum ; L, transverse section of the 

 posterior longitudinal fasciculus. 



thalaraus, which is otherwise exclusively composed of the upper 

 link of the projection system. 



