OCR Text |
Show 800 MR. F. E. BEDDARD ON THE [June 20, Behind the optic chiasma is a large somewhat heart-shaped elevation (c, d). It is divided auteriorly by a median furrow which is well-marked and deep; behind it shows indications of division into two. This elevation appears to m e to be the tuber cinereum and tbe corpora albicantia partly fused, but whose independence is still to be recognized on a careful examination. Fig. 2. Brain of Hydrochosrus, ventral view. Nat. size. s, pallium ; b, olfactory nerve ; a, origin of same ; c, tuber cinereum ; d, corpora albicantia ; p, pituitary body. Other features to be noted on the ventral surface of the brain will be seen by an inspection of the accompanying drawing. Fissures of the Hemispheres. I shall take as an assumed normal the best preserved of my three brains, indicating the divergences in arrangement which the others show. The most salient fissure is that lettered a (fig. 1). It runs almost from end to end of the brain ; at about the middle of its course it is bulged out on either side, and on the left side it is just interrupted by a bridging convolution, and is thus divided into two |