214 DISSECTION OF THE BRAIN. 



which is directed outwards over (the under surface of the cerebellum being 

 uppermost) the crus cerebelli, and is named flocculus, or subpeduncular 

 lobe (/). 



Dissection. To see the flocculus and the posterior medullary velum, 

 the biventral and slender lobes are to be sliced off on the left side, so that 

 the amygdaloid lobe may be everted from the valley (fig. 67). The floe- 



VIEW FROM BEHIND OF THE UNDER SURFACE OF THE CEREBELLUM, WITH SOME OF THE LOBES 

 REMOVED TO SHOW THE POSTERIOR MEDULLARY VELUM. 



a. Uvula. d. Furrowed band. 



e. Pyramid. /. Amygdaloid lobe, turned aside. 



b. Posterior medullary velum, with a bit of g. Medulla oblongata raised, showing posterior 



whalebone uud'-r it. surface. 



c. Subpeduncular lobe or flocculus. 



culus is laid bare by this proceeding, and passing from it to the tip of the 

 uvula is the thin and soft white layer of the posterior velum ; beneath the 

 last a bit of paper may be inserted. The furrowed band on the side of 

 the uvula can be fully seen now. 



Flocculus and medullary velum. The position of the flocculus to the 

 crus cerebelli has been before mentioned. This body (c) resembles the 

 other lobes in structure, and may be considered a rudimentary lobe ; for 

 it is divided on the surface into laminae, and contains a white medullary 

 centre which furnishes offsets to the laminae. 



Passing from the flocculus to the tip of the inferior vermiform process 

 (nodule) is the half of a thin white layer (6), the posterior medullary velum, 

 which serves as a commissure to the flocculi. On each side this band is 

 semilunar in form. Its anterior edge is free ; but its posterior border is 

 attached in front of the transverse furrowed band (d). In front of the 

 nodule the pieces of opposite sides are united. 



INTERIOR OF THE CEREBELLUM. In the cerebellum there is not any 

 cavity or ventricle inclosed as in the cerebrum. In the interior there is a 

 large white centre, corresponding with that of the cerebrum, which fur- 

 nishes offsets to the laminae, and to other parts of the encephalon. 



Dissection. For the purpose of seeing the medullary centre, with its 

 contained corpus dentatum, remove all the lamina? from the upper surface 

 on the left side. This dissection may be accomplished by placing the 

 scalpel in the horizontal fissure at the circumference, and carrying it in- 

 wards as far as the upper vermiform process, so as to detach the cortical 

 stratum. If the corpus dentatum does not at first appear, thin slices may 

 be made anteriorly tUl it is reached. 



