Wilder.] 554: [July 15, 



there is usually a deep notch which may be called the Incisura hypocampce 

 {Inc. Timp.). 



On the left side, the hemisphere was dissected ofi so as to leave two cvit 

 surfaces. One of these surfaces is plane and nearly horizontal, and lies at 

 about the level of the dorsal end of the postgetiiculatum [pgn.). The other 

 is convex, and extends from the cephalic border of the former obliquely 

 to the ventral surface of the brain ; it corresponds closely with the cephalic 

 border of the Tr actus opticus (Tr. op.). 



The left medicornu is cut at about the middle, and at nearly a right 

 angle with its course ; hence its lumen presents its characteristic crescentic 

 section, the ental boundary being the convex surface of the hypocampa 

 (Jimp.). 



The cephalic margin of the medicornu is here seen to reach the surface 

 of the hemisphere close to the Tractus opticus, and this narrow line of in- 

 terruption of the true nervous wall of the cornu constitutes the rima. The 

 scale upon which this figure was drawn did not permit the relations of the 

 pia, the velum, and the proplexus to be shown, and the undulations of the 

 ectal surface, corresponding with the FF. hypocampa} and fimbi'icB, and the 

 fasciola and fimbria are hidden by the projecting postgeniculatum. 



Most of the cephalic portion of the brain has been removed, but the 

 Portio de2)ressa {Pt. d.) of the prmperforatus is seen, with part of the Pt. 

 prominens {Pt. p.). The removal of most of the chiasma {cJi.) exposes the 

 form and extent of the Recessus opticus (B. op.). I 



The pons has been transected obliquely, and its caudal portion removed 

 together with the rest of the epen. and the metencephalon. 



The left Crus (Or. cb.') is seen in its whole length, excepting a small 

 part concealed by the slightly projecting cephalic border of the pons. 

 The well-marked cimbia {cmb.) may perhaps be regarded as the boundary 

 between the diencephalic portion of the crus {Pt. dien.) and the mesen- 

 cephalic portion {Pt. msen.), which more directly supports the optici and 

 postoptici; in man, this part seems to be almost wholly concealed by the 

 pons. 



The right JV. oculomotorius (iV". ocm.) is seen to emerge from the crus 

 just caudad of the mesal end of the cimbia, and just laterad of the Sulcus 

 intercruralis lateralis {SI. ic. I.). A marked longitudinal ridge of the crural 

 fibres separates from the postgeniculatum Cpgn.) the depressed area which, 

 from its forming approximately the fourth of a circle, I have called the 

 quadrans (g.). 



The albicantia {ahn) are more closely united tlmn in man, but they are 

 large, white, and perfectly distinguishable. The shallow farrow between 

 them, together with the u-shaped furrow which forms their cephalic 

 boundary, may be named Sulcus triradiatus (SI. trd.). 



The hypophysis has been removed so as to expose the Tuber cinereum 

 {T. cin.), and the thin raised margin of the Fm. infundibuU (Fni. inf.). 



Just caudad of the albicantia, and partly overhung by them, is a small 

 triangular depressed space with distinct perforations ; this seems to be the 

 true postperforatus (ppif.). 



