324 Proceedings of Boyal Society of Edinburgh. [mat 7, 
r.b, an oval area of white fibres, mostly running longitudinally, 
several strands run transversely into the irregular network on its 
outer margin ; this network passes round lateral ventricle, within 
the internal capsule, and may he connected with {c.n.) caudate 
nucleus; the strand r.h. is evidently the backward prolongation of 
strand spt. ; /, fornix — of normal size, but very lateral in position, 
intimately connected with the strand r.&. ; g.f gyrus fornicatus; 
c.s, callosal (f) sulcus — between gf. and r.h ; ^.c, internal capsule — 
again normal in size ; c.r, corona radiata — many fibres again traced 
over the area r.h. into gyrus fornicatus, as well as into other con- 
volutions at vertex; o.t, optic thalamus; e.c, external capsule; 
cl^ claustriim ; i, island of Eeil ; temporal lobe ; f.s, fissure of 
Sylvius ; o, optic tract. 
Fig. 6. Transverse section, through pulvinar of optic thalamus; 
r.h., backward continuation of area r.h. (fig. 5), some of its fibres 
traced outwards for a short distance (see the dark shaded part) 
along upper wall of lateral ventricle; /., fornix, body, in intimate 
relation to area r.h.; /., fimbria of fornix, in intimate relation to 
{g.d.) fascia dentata, and {c.amm.) cornu ammonis. 
Fig. 7. I.V., posterior cornu of lateral ventricle, much dilated; 
o.r., optic radiation of Gratiolet (c/. figs. 20 and 25); t., a thin band 
of fibres, between optic radiation of Gratiolet and ependyma of 
ventricle. Note the absence of all callosal fibres. This tract has 
been very carefully drawn from both naked eye and microscopic 
sections. i.I.f., inferior longitudinal fasciculus. 
Fig. 8. Transverse longitudinal section of right hemisphere, above 
the level of the lateral ventricle. Shows the remarkable shortness of 
the frontal lobe; f.r., fissure of Eolando; f.r.x, the abnormal 
Eolando (fig. 2) on the mesial aspect of the hemisphere. The 
crowded grouping of convolutions at the bottom of the fissure 
should be noted. This probably explains the shortness of the 
frontal lobe, the gyri, which should normally have been on the 
mesial surface, and extended round the tip of the lobe, being com- 
pressed into this position. In the absence of evidence of constric- 
tion by any malformation of the falx or membranes, it is probably 
a result of repression of the forward growth of the hemisphere 
during its development. 
Fig. 9. Transverse longitudinal section of same hemisphere, above 
