75 



commissural iSbers of the cerebellum. Note the shape of the dentate 

 nucleus and compare with the nucleus of the olive (i66). Can you 

 identify the fibers of the pre- and post-peduncles of the cerebellum ? 

 Compare with 169 for the general structure of the cerebellum. 



171. Cerebellum. Cat (young). Golgi's rapid method 

 (§141) ; collodion ; sections fx, cutting the folia transversely. 



This preparation will afford a demonstration of the extent of the 

 dendrites of the Purkinje cells, the basket cells of the molecular 

 layer, and possibly the dendrites and neurites of the granules of the 

 granular layer, neuroglia cells, and nerve fibers. 



CEREBRUM. 



Gross anatomy. Consult the preparations, studying them 

 carefully so that you may have clearly in mind {a) the relative size 

 and position of the cerebrum, {b) that it consists of two halves con- 

 nected with each other (principally) by a large commissure, the cal- 

 losum, (c) the incision of its surface by deep depressions, fissures, 

 dividing it into gyres, (a?) the aspects of the cerebrum- dorsal^ 

 frontal, occipital, mesal, temporal. The cinerea of the cerebrum 

 comprises (/) the superficial cortex and the hippocamp, (^) masses 

 deeply situated, of which the most important are the caudatum, and 

 lenticula, with which may be considered the closely associated thala- 

 mus and subthalamus. Examine the series of sections through the 

 cerebrum, noting the cortex and the location of these masses of cine- 

 rea, their relation to each other and to the cavities of the diencephal 

 and cerebrum. 



172. .Cerebral cortex. Cat. Transection of a portion at the 

 dorso-mesal angle, including the callosum ; 95% alcohol ; parafiin ; 

 sections )jl. Stain with hematoxylin (2-3 hours) and picro- 

 fuchsin. 



The points to be noted are (a) the transected gyres with the 

 septums of pia in the fissures, (6) the structure of the cortex upon 

 the summit of a gyre and at the bottom of a fissure. Can you recog- 

 nize the (four) ill-defined layers ? Note the number, shape and size 

 of the nerve cells, and compare with 71 and 173. 



173. Cerebral cortex. Cat (young). Golgi's rapid method 

 (§ 141) ; collodion ; sections p. ; in clearer. Mount in balsam 

 without a cover- glass. 



