366 DR. G. ELLIOT SMITH ON 



paraflocc/rhs dorsalis, by menus of a liand of grey substance. This arrangement also 

 exists in Orycteropns, but the larger dimensions of the area crescens have hidden the 

 connecting baud. Bulging downward upon the lateral side of the ^lyramid, the area 

 crescens seems to cut off the pyramid from all connection with the lateral parts of the 

 organ ; but if the area crescens be raised, a narrow flattened band will be found arching 

 downward from the pyramid into continuity -oith the paraflocculus dorsalis. 



We are now in a position to understand the course of ihe fssKrafloccuIi, of which 

 little has been said. The floccular fissixrc separates the floccular lobe from the area 

 crescens of the central lobe. It begins anteriorly at the columna cerebelU, proceeds 

 in the caudal direction around the lateral pole, then obliquely backward on the 

 dorsal surface of this pole tintil it reaches the posterior surface ; it then proceeds 

 obliquely toward the mesial plane, at the same time inclining doAYnward ; after 

 reaching the ventral margin of this surface it bends sharply upward on the mesial 

 side of the area crescens, and crosses tlie mesial plane as the tipper limiting furrow (<?) 

 of ihe pyramid. 



The area crescens is divided into three chief subdivisions by means of two deep 

 fissures which begin at its lateral margins and extend toward the mesial plane. The 

 more anterior of these fissures, which we may distinguish as a, begins on the anterior 

 surface of the cerebellum, in close proximity to the point where the Jissura prima reaches 

 the columna cerehelli. From a surface-view the two clefts, Jissura a and the Jissura 

 prima, would appear to arise from a common stem, but a submerged folium really 

 separates them in the whole of their extent. The fissure a. extends vertically, and hence 

 it diverges from ihe Jissura prima. The two fissures thus come to be separated by an 

 anterior district which we may call the area A. The fissure a ascends vertically on the 

 anterior surface, and then proceeds directly backward on the dorsal surface, and then 

 arches mesially, and at a point about mm. from the mesial plane it joins a much 

 shallower transverse fissure, Avhich we may for convenience of description regard as part 

 of the fissure « (fig. 29). The region included between the fissure a and the Jissura 

 prima consists of the two laterally placed, oblique fusiform areas A and a mesial quadri- 

 lateral area. The latter is joined to the area A on each side by a narroAv neck. 



A second very deep fissure cuts into the lateral border of the area crescens, and this 

 we may distinguish by the letter h. The fissure h starts from the postero-lateral 

 margin of the area crescens at a point w^hich roughly corresjionds to the middle of 

 ihe Jissura Jlocculi. It cuts transversely into the central lobe, but suddenly comes to 

 a termination at a point about 5 mm. from the mesial plane. At this point we find a 

 shallow depression, which we may call the medullary area, for reasons which will be 

 evident later. For the sake of convenience of description, we may denominate a shallow 

 fissure which crosses the mesial plane at this point as part of ihe Jissura b. 



By means of the fissures a and b the broad expanded lateral part of the central lobe, 

 which we have called the area crescens, is divided into three regions, w^hich Ave may 

 distinguish as the areas A, B, and C respectively. The area C, the most caudally placed 

 of the three regions, is a large amygdaloid mass which projects backw-ard between the 

 lohus Jlocculi, on the late]al side, and the pyramid and lobus posticus on the mesial side 



