1888.] Dr A. Bruce on Absence of Corpus Callosum. 
329 
latter. Of the commissures, the anterior (a) was present and 
enlarged ; the posterior present, of normal size ; the middle absent. 
Fornix present, its psalterium absent ; septum lucidum {spt) probably 
present, as Eichler’s figures 11 and \\a represent two laminrn in the 
position of the triangular area (spt) in my case. Lateral ventricles 
dilated in their posterior horns (because corpus callosum absent). 
Lepto-meninges normal. On the medial surface the pia continued 
downwards to the margin of the fornix ; the choroid plexus normal ; 
the proper covering of the third ventricle is absent, probably torn 
in removing the falx of the dura. Lamina terminalis present. 
X. Urquhart, Brain, Oct. 1880. — Female, idiot, with deficiency 
of co-ordinating power over muscles. Attention, imitation, ideation, 
the moral sense feebly developed. Calvarium thin, extremely 
irregular in shape, shortened antero-posteriorly, nearly circular. 
Light side of skull flattened posteriorly, bulged slightly anteriorly, 
so that the hemisphere of that side was, as it were, pushed forward. 
Dura mater non-adherent. Cerebral hemisphere small. Convolu- 
tions small and simple, especially in the frontal and occipital lobes. 
Corpus callosum represented by a rudimentary ridge on each hemi- 
sphere. (From a drawing of the brain kindly sent me by Dr 
LTrquhart, I take this to closely resemble the ridge at the upper 
part of the white septum lucidum in my own case.) Gyrus forni- 
catus absent, numerous radiating convolutions taking its place. 
Fornix and septum lucidum absent. A thin pellucid extension of 
pia mater seemed to connect the hemispheres. 
XI. Anton, Zeitscbrift f. Heilkunde, vii. Bd. i. pp. 53-64, 1886 
(fig. 13). — Foetus, female. Born at 7th month; lived 6 hours. 
Skull normal in size and configuration. Falx major normal. Lepto- 
meninges not thickened. Both hemispheres nearly symmetrical. 
Poorly convoluted. Corpus callosum and psalterium of fornix 
quite absent. Anterior commissure also absent. Only trace of 
septum lucidum ispt) present. Fornix system (/) well developed ; 
the lepto-meninges came into direct contact with it. Middle com- 
missure of normal size. Gyrus fornicatus {gf.) small. Calloso- 
marginal sulcus {c.m.') only present in its posterior vertical part. 
Xervus lancisi {n.V) fused with the fornix, and passes into the 
fascia dentata (/.<i.) Parieto-occipital {p.o.) and calcarine (/c.) 
fissures do not unite. The lateral ventricles so dilated that Anton 
