63 
The lobes of the Mesencephal are quite small, with a median 
dorsal furrow between the lobes. The greatest dorsal width of the 
Mesencephal is at the anterior portion (Figs. 3 and 12), and it becomes 
much more narrow toward the posterior end (Fig. 13). Although the 
division of the lobes is not apparent very far back in a surface view, 
there is no line of demarcation apparent to distinguish the cerebellum 
or Epencephal. The sagittal section (Fig. 6), shows the cerebellum as 
scarcely more than a tiny fold, almost under the optic lobes, and the 
2---\----Dien. 
oo 
es sii} --Meten. 
Fig. 14. 
Fig. 12. 
Fig. 10. Transverse section of the Diencephal in the region of the portas. (An- 
niella pulchra.) po porta. fl floor of the fore-brain. 
Fig. 11. Transverse section of the Diencephal through the center, X 28. (An- 
niella pulchra.) 
Fig. 12. Transverse section of the Mesencephal, X 28. (Anniella pulchra.) 
Fig. 13. Transverse section in the region of the cerebellum, X 28. (Anniella 
pulchra.) 
Fig. 14. Transverse section of the Metencephal, X 28. (Anniella pulchra.) 
transverse section shows its slight extent in the region of the fifth 
nerve (Fig. 13). This accords with the theory of its function in complex 
activity, for no very complex motions could occur in a limbless form. 
The cellular structure too is very simple (Figs. 6 and 13). 
