354 



ANATOMY IN A NUTSHELL 



Then' arc numerous peduncles of the brain. Those of the cerebellum are 

 three pairs and are stout bundles of nerve fibres which connect the cerebellum 

 with other chief divisions of the brain. They are distinguished by their posi- 

 tion as superior, middle, and inferior peduncles or crura. The superior pair 

 emerge from the mesial part of the medullary substance of the hemispheres, and 

 run forward upward to reach the nuclei tegmenti of the opposite sides, after 

 decussation under the formatio reticularis. Also called (1) crura ad corpora 

 quadrigemina, (2) crura ad cerebrum, (3) processus cerebelli ad cerebrum, (4) 

 processus-e-cerebello ad testes. (.">) branchia conjunctiva, and (6) branchia con- 

 junctoria). (Plate CLXXXVIII). 



PLATE CLXXIV. 



Showing; Blood Supply of the External Surface of the Brain. 



The middle pair from the ventral transverse fibres of the pons, emerging 

 from the lateral part of the white substance of the hemispheres. (Also called 

 crura or processus ad uiedullani). (Plate CLXXXVIII). 



LESSON CI I. 



The fissures of the cerebellum are three in number — two vertical and one 

 horizontal. The great horizontal fissure is a continuous fissure which separates 

 the cerebellum into upper and lower portions. It begins in front at the middle 

 peduncles, and extend- around the outer and posterior border of each hemi- 

 sphere. 



The vertical ones are : 



1. Incisura cerebelli anterior, the anterior median notch of the cerebellum, 

 into which the corpora quadrigemina arc received. 



2. Incisura cerebelli posterior, the median notch on the posterior outline 

 of the cerebellum, formed by the projection of the cerebellar hemispheres be- 

 yond the vermis. (Plate CLXXXVIII). 



