THE STEUCTUEE AND CONNEXIONS OF THE CEEEBELLUM. 577 



Culmen 



of gray matter, which is folded on itself so as to enclose, in a flask-like manner, 

 a portion of the central white matter (Figs. 511 and 512). This gray capsule 

 is not completely closed. It presents an open mouth, termed the hilum, which 

 is directed medially and upwards, and out of this stream the fibres of the 

 brachium con- 

 junctivum. 



Three small ad- 

 ditional masses of 

 gray matter are also 

 present on each side 

 of the median plane 

 in the central white 

 matter of the cere- 

 bellum. These are 

 termed the nucleus 

 emboliformis, the 

 nucleus globosus, 

 and the nucleus 

 fastigii. The nu- 

 cleus emboliformis 

 or embolus is a small 

 lamina of gray 

 matter which lies 

 just medial to the 

 hilum of the nucleus 

 dentatus, being thus 

 related to it some- 



inferior olivary nucleus 



FIG. 511. SAGITTAL SECTION THROUGH THE LEFT HEMISPHERE 

 OP THE CEREBELLUM.' 



Showing the "arbor vitse" and the nucleus dentatus. 



what in the same manner that the medial accessory olivary nucleus is related to the main 

 inferior olivary nucleus. The nucleus globosus lies medial to the nucleus emboliformis and on a 

 somewhat deeper horizontal plane. The nucleus fastigii or roof nucleus is placed in the white 

 substance of the vermis close to the median plane and its fellow of the opposite side. It is, 

 "lerefore, situated on the medial aspect of the nucleus globosus. 



mrm 



! 

 Stria terminalis 



Pulvinar of the thalamus 

 Inferior colliculus 



Brachium pontis 



j~ Third ventricle 



i-Si Tsenia thalami 



\ , 

 a,----Trigonum habenulse 



_ . Pineal body 

 - Superior colliculus 



Inferior brachium 

 Trochlear nerve 



- Velum medullare anterius 

 - Brachium conjunctivum 



Nucleus dentatus 



512. From a dissection by Dr. Edward B. Jamieson in the Anatomical Department of the University of 

 Edinburgh. The nucleus dentatus is displayed from above and the), brachium conjunctivum has 

 been traced from it to the mesencephalon. 



The nucleus dentatus and the emboliform nucleus present a structure very similar to that of 

 the inferior olivary nucleus. In the nucleus globosus and the nucleus fastigii the cells are some- 

 what larger in size. 



Cerebellar Peduncles. These are three in number on each 



side, viz., 

 38 



the 



