LESSER CEREBRO-SPINAL LYMPH 



127 



FIG. 51. VIEW OF THE INNER SURFACE OF THE RIGHT HALF OF THE 



FOETAL BRAIN OF ABOUT six MONTHS. (From Reichert.) 



F, frontal lobe ; P, parietal ; O, occipital ; T, temporal ; I, olfactory bulb ; II, right 

 optic nerve ; f/>, calloso-marginal fissure ; p, external ; />', internal parts of the 

 parieto-occipital fissure; h, calcarine fissure; g, gyrus fornicatus ; c,c, corpus 

 callosum ; s, septum lucidum ; f, placed between the middle commissure and the 

 foramen of Monro ; v, in the upper part of the third ventricle immediately below 

 the velum interposituin and fornix : z/, in the back part of the third ventricle 

 below the pineal gland, and pointing by a line to the aqueduct of Sylvius; v" , in 

 the lower part of the third ventricle above the infundibulum ; r, recessus pinealis 

 passing backwards from the tela choroidea ; /?', pons Varolii ; Ce, cerebellum. 



FIG. 52. TRANSVERSE SECTION THROUGH THE BRAIN OF A SHEEP'S 

 EMBRYO OK 2.7 CM. IN LENGTH. (From Balfour, after Kolliker.) 



The section passes through the hemispheres and third ventricle, st, corpus striatum ; 

 th, optic thalamus ; (, third ventricle ; c', their divergence into the walls of the 

 hemispheres ; /, lateral ventricle with choroid plexus//; h, hippocampus major ; 

 f, primitive falx ; a, orbito-sphenoid ; sa, presphenoid ; /, pharynx ; c/i, chiasma ; 

 o, optic nerve ; mm, foramen of Monro; s, covering of lateral ventricles. 



