MR. FLOWER ON THE BRAIN OF THE JAVAN LORIS. 105 



of the " postero-parietal" (scissure de Rolando) or of the "angular" sulcus', both so 

 well marked in all the larger Apes. The sulci being mostly short, or only, as it were, 

 partially developed, the boundaries of distinct gyri or convolutions are not very clearly 

 marked out ; indications of most of those that are present in the ordinary Quadrumana 

 may, however, be traced, except perhaps those of the parietal region, which is altogether 

 much reduced. 



B. Sulci of the inner face of the hemisphere (fig. 4). The inner face of the hemi- 

 sphere is generally smooth, but has several deeply cut and well-defined sulci, without 

 any secondary indentations. 1, The " calloso-marginal" sulcus (i) is quite simple, 

 except at ils anterior end, where it is slightly bifurcated. It rather exceeds the corpus 

 callosum in length, and is placed about midway between this and the upper margin of 

 the hemisphere. 2. The " calcarine " sulcus (/) extends from below the hinder end of 

 the corpus callosum backwards almost to the apex of the hemisphere, is slightly curved, 

 with the concavity downwards, and joined about midway by (3) a perpendicular fissure 

 {k) resembling the " occipito-parietal " {scissure perpendiculaire interne), and which 

 does not extend quite so far upwards as the margin of the hemisphere. 4. The 

 "dentate" sulcus (»i) offers nothing remarkable; the calcarine appears to run into it, 

 but becomes so shallow at the point of junction as scarcely to intercept the union of 

 the callosal with the uncinate gyrus. The dentate gyrus (20) is broad and, as usual, 

 becomes continuous with the uncinate (19) at the lower end of the sulcus. The corpus 

 fimbriatum, as seen in this view, is very broad at the upper part ; and below, it joins 

 with the two gyri last named. There is no indication of the " collateral " sulcus. 

 Fig. 3 exhibits well the proportionate length of the corpus callosum to the other parts 

 of the cerebrum. The total length is 1'3 inch, of which the corpus callosum is •6.'5, 

 the portion anterior to it is 2, and that behind it "45. 



The under surface of the brain (fig. 2) presents the following characters: — The 

 olfactory lobes in their anterior half are compressed, and of equal width almost to their 

 termination ; posteriorly they become flat, and widen out backwards to their attach- 

 ment to the under surface of the anterior lobe. The fissure of Sylvius divides them 

 from the temporal lobe. This fissure is at this spot less deep than it is higher up on 

 the side of the hemisphere, but it is not actually intercepted by the base of the olfactory 

 lobe, as it is in the Carnivora, Ruminantia, and other inferior mammals. The orbital 

 surface of the hemisphere, as seen on each side of the olfactory lobes, is hollowed out, 

 and presents the simple longitudinal sulcus before mentioned. The optic nerves are 

 small for the size of the brain ; behind their commissure is a prominent, round, whitish 

 mass, filling up the greater part of the interpeduncular space, in which the corpora 

 albicantia are not clearly distinguished from the tuber cinereum. The pituitary body 

 is flat, of roundish outline, but broader in front than behind, attached by a narrow 



' As the arched sulcus which bounds the upper margin of the " angular gyrus " {pli courbe) does not appear 

 to have received a name heretofore, I have called it as above. 



p2 



