776 



DISSECTION OF THE BRAIN. 



Prepare 

 cerebellum. 



Parts to be 

 separated 



SECTION V. 



THE CEREBELLUM. 



Dissection. The cerebellum is to be separated from the remains 

 of the cerebrum by carrying the knife through the optic thalamus, 

 so that the small brain, the corpora quadrigemina, the crura 

 cerebri, the pons, and the medulla oblongata may remain united 

 together. 



Any remaining pia mater is to be carefully removed from the 



Pons. 



Culmen. 



Declive. 



Post central 

 " sulcus. 



Pre-clival 



sulcus. 



Post- 

 clival 

 sulcus. 



Folium cacuminis. 



FIG. 284. THE UPPER SURFACE OP THE CEREBELLUM. 

 The chief sulci are represented by thick lines. 



from one median groove on the under surface ; and the different bodies in that 



other. hollow are to be separated from one another. Lastly, the handle of 



the scalpel should be passed along a deep sulcus (the horizontal 



fissure) at the circumference of the cerebellum, between the upper 



and under surfaces. 



Form and The CEREBELLUM or small brain (figs. 284 and 285) is oval in 

 shape, and flattened from above down. Its longest diameter, which 

 is directed transversely, measures about four inches. This part of 



position of the encephalon is situate in the posterior fossa of the base of the 

 skull, beneath the tentorium cerebelli. Like the cerebrum, it is 

 incompletely divided into two hemispheres ; the division being 

 marked by a wide median groove along the under surface, and by 

 a notch at the posterior border into which the falx cerebelli pro- 

 jects. The narrower part along the middle line uniting the two 

 hemispheres is known as the worm (vermis). 



nm - 



Division 

 into two. 



