Herrick, Morphology of Nervous System. 37 



Fig. 8. Portion of the olfactory cortex, with its three sorts of cells. 

 Figs. 9-11. Views of the brain in three positions. 

 (All the figures of this plate were drawn with the aid of the camera 

 lucida). 



PLATE IV. 



Figs. 1-11. A series of transverse sections through the mesen- 

 cephalon and metencephalon pf the lizard, especially to illustrate the re- 

 lation of the cerebellum to adjacent parts. 



Explanations of these figures will be given in the second part of the 

 paper. 



Fig-. 1. Section just cephalad to the optic lobes, a, nidiilus of the 

 substantia nigra; the reference line passes through the optic tracts and 

 substantia nigra. 



Fig. 2. Section through the middle of the optic lobes. lM.l>., Mey- 

 nert's bundle. 



Fig. 4. Illustrates the relations at the base of the cerebellum and 

 exit of the eighth nerve. The free tip of the cerebellum, having re- 

 curved to beyond the origin, appears as an independent organ. 



Figs. 5-9. Indicate the method of retroflexion by which the cere- 

 bellum is formed. 



Fig. 12. Cells from the nidulus of the substantia nigra. See Fig. 

 I, a. 



Fig, IS. Cells from the root of the tenth nerve, drawn with a one- 

 fifth inch objective. 



Fig. 15. Cells from the frontal lobe (see Fig. 6, v, Plate IX). 



Fig. 16. Cells from the intra-ventricular lobe of the same section 

 at v. 



plate' IX. 



A series of horizontal sections through the brain of the lizard. 

 The descriptions will be extended in Part II. 



Fig. 1. Section near the ventral surface. (/, tuber cinerium. 



Fig. 2. Section at a higher level. P, peduncles; a. nidulus of the 

 nigra; op.f., optic tracts. 



Fig. ,). J\f.b., Meynert's fasciculus; iii.f., posterior longitudinal 

 fasciculus. 



Fig. 4. Section at the level of the corpus callosum. 



Fig. C. F./., frontal lobe; F.m./., fronto-median lobe; O./., occipi- 

 tal lobe; A/.L., intra-ventricular lobe; A. P., foramen of Munro; A.L., 

 central division of axial lobe; O.t., optic tracts; O.c, posterior or optic- 

 lobe commissure; Al.b., Meynert's bundle; O.v., optic ventricle; H., 

 habena; t.p.fr., tract to corpus posterius; v" and v.," see Figs. 15 and 

 16, Plate IV. 



Figs. S-9. (' .p., corpus posterius. 



