Explanation of Plates. 159 



Plate XI. 



Sections in various planes through the brain. 



Fig, 1. — Posterior portion of a horizontal section through the 

 hemispheres and optic lobes, below the level of the superior 

 commissure. Ac, ascending fibres from the region of the 

 anterior commissure; t. th., taenia thalami; p. c, posterior 

 commissure; a., fibres to corpus posterius; &., posterior optic 

 tracts. 



Fig. 2. — Section near the posterior margin of the optic lobes. 



Fig. 3. — Section at the exit of fourth nerve. 



Fig. 4. — Horizontal section at the level of the corpus callosum. 

 c. c, corpus callosum; 0. /., olfactory tracts; /., fornix; p. t., 

 peduncular tracts; a. c, anterior commissure fibres. The 

 index line points to a locus where there are apparently other 

 fibres entering the thalamus from the hemisphere; c. gn., 

 corpus geniculatum ; 0. tr., optic tracts. 



Fig. 5. — Section through medulla and cerebellum at the crura 

 cerebelli. V. n., motor nucleus of the fifth nerve; I?., locus 

 of transverse multipolar cells (Fig. 12, Plate VII.). 



Plate XI J. 



Sections through the optic lobes and thalamus. 



Fig. 1. — Section through the hemispheres and thalamus anterior 

 to the middle commissure. /. th., taenia thalami; /. a. , 

 fibrae ansulatae (?); 0. tr., optic tracts. 



Fig. 2. — Section behind the superior commissure and through the 

 optic lobes, a. and b., portions of the tectum drawn upon 

 an enlarged scale in Figs. 7 and 8; col., colliculi. 



Fig. 3. — Transverse section through the optic lobes at the level of 

 the third nerves, tec, tectum opticum; col., colliculi; d. t., 

 descending decussating tract from the optic lobes; n. III., 

 nucleus of oculomotor nerve. 



Fig. 4. — Section through thalamus at the median commissure. 



Fig. 5. — Section through thalamus at the posterior commissure. 

 c. gn., corpus geniculatum;/. a., fibrse ansulatae; (?) p. c, pos- 

 terior commissure. 



