STRUCTURE OF THE LOBES OF THE CEREBRUM. 403 



Fig. 241. 



Fig. 241. Transparent sagittal section of the brain carried through 

 the internal olfactory convolution not far from its internal sur- 

 face, from the Guineapig. F, The frontal extremity ; 0, the occi- 

 pital extremity of the cerebral lobe ; RR, cortex ; BB, the external 

 layer ; 8, section of a sulcus ; Bl, the corpus callosum ; + + + , per- 

 foration of the transverse section of the callosal fasciculi by the 

 connecting systems of the cortex of the olfactory lobe and of the 

 gyrus fornicatus ; Sp, superficial medullary layer of the internal 

 olfactory convolution ; m, fasciculi of the gyrus fornicatus ; Ah, the 

 cornu Ammonis ; L, fasciculi of its formatio reticularis, which become 

 the nerves of Lancisi ; G, the fornix ; JP, the septum pellucidum ; St, 

 pedunculus septi ; J, prolongation of the mass of the corpus striatum 

 into the septum internal to the lamina perforata anterior ; C, anterior 

 commissure; I, cerebral ventricle ; Z, pineal gland ; Z', the ganglion 

 of the habenula ; m', section of the medulla of the corpora quadri- 

 gemina, which is prolonged into the posterior commissure and the 

 pineal gland ; A, the aqueduct ; Th, optic thalamus ; ma, corpus 

 candicans (albicans) ; Cx, cms cerebri ; i, the fasciculi of the teg- 

 mentum proceeding from the ganglion of the stile of the pineal gland; 

 n, pituitary body ; m, nervus oculomotorius ; 8, the posterior lon- 

 gitudinal fasciculi ; Br, point of decussation of the connecting arms ; 

 Pd, the olfactory lobe ; Bf, prolongation of the cortex of the inter- 

 nal olfactory convolution beneath the frontal extremity of the gyrus 

 fornicatus ; QQ f J corpora quadrigemina. 



D D 2 



