THE BRAIN AND ITS MEMBRANES. 



731 



of the corresponding sulcus valleculce (see above), which deepens as it runs for- 

 ward along the side of the inferior worm. The postero-inferior lobule is as large, 

 taken as a whole, as the larger lobules of the upper surface of the hemisphere. 

 It resembles them also in general appearance, except that it is much more convex 

 and its intralobular fissures are very large. These fissures are also considerably 

 more curved, concavity forward, than those of the upper surface. Two of them 

 are of especial depth ; hence the postero-inferior lobule is often described as being 

 made up of three subdivisions, the most posterior being called the inferior semi- 

 lunar lobule ; the middle one, the posterior slender lobule ; and the anterior, the 

 anterior slender lobule (lobuli graciles). In examining the mesial extremities of 

 these " sublobules " it is found that only that of the inferior semilunar actually 

 joins with the tuber valvulse, while those of the other two terminate abruptly in 

 the sulcus valleculse, and do not join with any lobule of the inferior worm. 



Central lobule 



.Sup. med. velum 



Sup. cerebel. ped. 

 Module 



Mid. cerebel. ped. 

 Inf. cerebel. ped. 

 (the inf. velum is seen 

 just beyond the end 

 >f the line). 



Post.-sup. 

 fofetfa 



Cut surface 

 of flocculus 



Cut surface of 

 part of mid. ped. 



Digastric lobe \plocculus 

 Amyqdala (mesial to the 

 Ime) 



FIG. 432. The cerebellum from in front, with pens and medulla removed. (Henle.) 



Therefore the post-pyramidal fissure (see above) is prolonged, on the hemisphere, 

 in front of the anterior slender lobule. 



Pyramid and Digastric Lobules (Figs. 432, 433 ; also preceding ones). The 

 pyramid is a large laminated, somewhat conical projection. Its cut surface shows 



Cut surface of 

 mid. 



Sup. velum Kbdulug 



Inf. velum 



Vvula 



Pott, pyram. Hollow after removal 



oj "tonsil TOnsU 



FIG. 433. The cerebellum from in front and below. (Henle.) 



numerous intralobular fissures. On each side of it is the sulcus valleculae, here 

 quite deep, and it is connected, across this sulcus, with the digastric lobule by 

 means of a narrow connecting ridge of gray matter. 



The digastric (biventral) lobule (see also Fig. 434) is triangular in general out- 



