78 LABORATORY OUTLINE OF NEUROLOGY 



Enter the pyramidal tract in the sketches, consulting Herrick 

 ('15), Fig. 75, for its position in the cerebral peduncle. The 

 following references are also suggested: Bailey ('16), Fig. 331, 

 p. 486; Cunningham ('15), Fig. 480, p. 545; King ('11); Morris 

 ('14), Fig. 664, p. 841, and Fig. 706, p. 897; Piersol ('13), Fig. 

 1026, p. 1187; Rauber-Kopsch ('07), Figs. 689, 690, pp. 627, 628; 

 Toldt ('09), Fig. 1216, p. 790; Fig. 1229, p. 800; Villiger ('12), 

 Figs. 176, 179, 181, 182. 



95. Dissection of the pyramidal tract. — The pyramidal tract 

 can readily be dissected in the brains of the sheep and of man. 

 If only one human brain is to be dissected and it is desired to 

 make the optional dissections, this tract should not be exposed 

 in this specimen at this time (see Section 138) . 



On the right half of the brain of the sheep (see Fig. 8) locate 

 the pyramid on the ventral surface below the pons. Strip the 

 pons fibers back from the cut median surface for a short distance 

 so as to expose the longitudinal pyramidal fibers dorsally of 

 them. In the sheep the pyramidal fibers will be found to inter- 

 digitate with those of the trapezoid body and one or the other of 

 these systems will have to be partially destroyed to expose the 

 other. In following the pyramidal tract spinalward, careful 

 teasing will separate its fibers as far down as their decussation, 

 below which they can no longer be dissected. For their spinal 

 course see King ('11). 



From the pons upward the pyramidal tract can be dissected 

 through the cerebral peduncle, the number of associated cortico- 

 pontile fibers being much less than in man. The further dis- 

 section of the pyramidal tract through the cerebral hemisphere 

 should be deferred (see Sections 138 and 150). 



7. Structure and Connections of the Cerebellum 



96. The cerebellar peduncles. — There are three of these pe- 

 duncles: the superior (brachium conjunctivum) , the middle 

 (brachium pontis), and the' inferior (corpus restiforme). 



(a) Gross structure. — The cerebellar peduncles have been sev- 

 ered in both the human and the sheep's brain (Section 49). 

 Examine their cut surfaces on the dorsal aspect of the medulla 

 oblongata (for the sheep see Fig. 11). With the orange-wood 



