538 



THE CEREBRUM. 



the foetus they are at first blended together, and they become separated about the 

 beginning of the seventh month. In most vertebrate animals there is but one white 

 eminence or corpus albicans in their place. 



Fig. S68. Fig. 368. VIEW FROM 



BEFORE OF THE ME- 

 DULLA OBLONGATA, 

 PONS VAROLII, CRURA 

 CEREBRI, AND OTHER 

 CFNTRAL PORTIONS OF 

 THE ENCEPHALON. 



On the right side the 

 convolutions of the cen- 

 tral lobe or island of Eeil 

 have been left, together 

 with a small part of the 

 anterior cerebral convolu- 

 tions : on the left side 

 these have been removed 

 by an incision carried 

 betweon the thalamus 

 opticus and the cerebral 

 hemisphere. 



I', the olfactory tract 

 cut short and lying in its 

 groove between two con- 

 volutions ; II, the left 

 optic nerve in front of 

 the commissure^; II', the 

 right optic tract ; Th, 

 the cut surface of the left 

 thalamus opticus ; C, the 

 central lobe or island of 

 Reil ; Sy, fissure of 

 Sylvius ; x x , locus 

 pevforatus anterior ; e, 

 the external, and i, the 

 internal corpus genicu- 

 latum ; h, the hypophysis 

 cerebri or pituitary body ; 

 tc, tuber cinereum with 

 the infundibulum ; a, one 

 of the corpora albicantia ; 

 P, the cerebral peduncle 

 or crus ; /, the fillet ; 

 III, close to the left 

 oculo-motor neive ; x, 

 the locus perforates pos- 

 ticus; PV, pons Varolii ; 



V, the greater root of the fifth nerve ; +, the lesser or motor root ; on the right side 

 this + is placed on the Gasserian ganglion, arid points to the lesser root, where it proceeds 

 to join the inferior maxillary nerve ; 1, ophthalmic division of the fifth nerve ; 2, superior 

 maxillary division ; 3, inferior maxillary division ; VI, the sixth nerve ; VII a, the 

 facial ; VII b, the auditory nerve; VIII, the pneumo-gastric nerve ; Villa, the glosso- 

 pharyngeal ; VIII b, the spinal accessory nerve ; IX, the hypoglossal nerve ; fl, the floc- 

 culus ; fh, the horizontal fissure of the cerebellum (Ce) ; am, the amygdala; pa, the 

 anterior pyramid ; 0, the olivary body ; r, the restiform body ; d, the anterior median 

 fissure of the spinal cord, above which the decussation of the pyramids is represented ; 

 ca, the anterior column ; cl, the lateral column of the spinal cord ; C I, the suboccipital 

 or first cervical nerve. 



The tuber cinereum is a lamina of grey matter extending forwards from 

 the corpora albicantia to the optic commissure, to which it is attached, and 

 forming, as afterwards described, part of the floor of the third ventricle. 



ca 



