Tin-: 



849 



The anterior columns or pillars of the fornix arc two separate, cylindrical 

 bundles which pass forwards from the apex of the body of the fornix and then turn 

 sharply downwards along t he anterior boundary of t he t hird ventricle, just behind the 

 anterior cerebral commissure. A part of each column, the free portion, forms the 

 anterior boundary of the interventricular foramen (Monroi). Thence n sinks into 



the grey substance of the lateral wall of the third ventricle (the Covered /mrtion), and 

 passes ventral wards to the ba>e of the brain, where it appear* on the exterior as the 

 corpus mammillare (rig. (II!)). Someof its fibres are interrupted in the nuclei of the 

 corpus mammillare. chiefly in its lateral nucleus; probably most of them merely 

 double back, forming a geim. From the corpus mammillare the fibres are disposed in 



I i'.. 031. HORIZONTAL SECTION OF TELENCEPHALON SHOWING BODY OP FORNIX AS SEEN FROM 

 BKI.OVV AND THE ANTEHioH CoMMissruK IN SECTION. (After Toldt, " Atlas of Human 



Anatomy," Mebmaii, London and Xr\v Y'ork.) 



/. i 1:1 1 1. i-Ai-riii: r .1 /./:. i t IIIKM '. i: < 



l:i:.\l ill' rn/.TI x 



ROSTRCM OF CORPUS CALLOHDI 



/ IIKA1) (IF l-.d-JIA Ti: XCrLKrs 



AXTKliim; CERE- 



in: IL i -i i. MM /r /./: 



PA1.L1DCS 



I'IIYI:I;I:I> riii:rinx nr 



Of 1--<>I;X1.\- 



/, 1/7.7.' IL CERE k, 

 ///.'. I /, r/.W , 

 (S YI. I'll i 



CLAU8TRUM 



: /: v i /. 

 r.l/'.w IE 



xn i.r i a 



II II: I \TI..K 



fXTK/lX I /. - 

 CAPSULE 



in 

 ii ATI-: xi 



CORK 



I HA I. 



VENTRICLE 



- IT i. rrxAR 



lliri'lll-A.Ml'l S 



FIMBRIA 



/.T.N- '// nu:M.\ 



xri i:\ir.-\i OF 

 CORPUS 



>; i /.T.S- i-i\t;rr.l 



PARIETO-OCCIPITA 



LONOITUDIltAl 



Fiaauits 



Ml. Ill i/. xri:i-.ii-K OF 

 HEM1XPII 



at least t hn-e ways: (1) The greater part perhaps pass directly upwards and are lost 



in the null rior nucleus <>/ tin' tlmldinnx. where they ramify freely and terminate among 

 its cells. These fibres form the bundle known as the thalamo-mammillary fascicu- 

 lus, or bundle of Yicq d'Axyr; (;_') a portion of the fibres join the cerebral peduncle 

 near by as the pedunculo-mammillary fasciculus, and pass caudahvards. The 

 destination of these is still obscure. Probably they go to the interpeduncular 

 ganglion, the red nucleus, and the nuclei of the medulla oblongata: C5) a portion 

 of the fibres decussate in the basal or dorsal parts of the corpora mammillaria and are 

 distributed to both the thalamus and cerebral peduncle of the opposite side. 



54 



