Human anatomy, including structure and development and practical considerations . dually downward on each side to the lateralmargins of the hemispheres, whilst it falls off more rapidly towards the posteriornotch. The lower surface of the cerebellum is much less regular, owing to the pres-ence of a wide median groove, the vallecula, that is bordered laterally by therounded hemispheres and is continuous in front and behind with the anterior andposterior notches. The bottom of the vallecula is occupied by the irregular ridge-likesurface of the middle lobe which is here known as the vermis inferi
Human anatomy, including structure and development and practical considerations . dually downward on each side to the lateralmargins of the hemispheres, whilst it falls off more rapidly towards the posteriornotch. The lower surface of the cerebellum is much less regular, owing to the pres-ence of a wide median groove, the vallecula, that is bordered laterally by therounded hemispheres and is continuous in front and behind with the anterior andposterior notches. The bottom of the vallecula is occupied by the irregular ridge-likesurface of the middle lobe which is here known as the vermis inferior. The frontof the valley receives the dorsal surface of the medulla. The cerebellum is incompletely divided into an upper and a lower part by a deepcleft, the great horizontal fissure (sulcus .horlzontalis cerebelli). The sulcusbegins in front, at the side of the middle cerebellar peduncle, by the junction of twodiverging limbs that embrace the three cerebellar peduncles. It passes usually con-tinuously around the circumference of ihe cerebellum, but sometimes is interrupted. Pyramis Mesial sagittal section of brain-stem and cerebellum, showing fourthventricle, Sylvian aqueduct, and cerebellar worm. T084 HUMAN ANATOMY. on the worm, and cuts (lcxj)ly into the lateral and posterior portions of the hemispheresand the worm behind. It is, howe\er, \isible on the upper aspect of the cerebellumonly for a short distance as it a])proaches the ])osterior notch, the remainder of itscourse beinj^- masked by the oxerhanj^ing border of the hemisphere. Althouj^hof cardinal importance in the usual description of the human cerebellum, the greathorizontal sulcus is of secondary morphological significance, being a secondaryfissure that is developed relatively late in man and feebly or not at all in manyother animals. Both the vermis and the hemispheres are subdivided into tracts, or lobules, bythe deeper fissures ; these are grouped into lobes, in the conventional division ofthe human cerebellu
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Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
