EXPLANATION OF PI.A TES. 



The sections are all drawn, unless otherwise stated, by means of the camera 

 lucida. 



PLATE L 



C. L. Hkrrick. 



Transverse sections of the right hemisphere of Arctomys to a uniform scale. 



Fig. I. Cross-section of olfactory bulb. Cf. Fig. 9. 



Fig. 2. Cross-section of hemisphere and crus olfactorius. 



F/g. 3. Cross-section of hemisphere at the junction of the crus olfactorius. 



Figs. 4-S. Sections taken at frequent intervals across the hemisphere, ex- 

 tending as far caudad as the corpus callosum. 



Fig-. 9. Enlarged section of the lobus olfactorius. Compare also Plate II, 

 Figs. 1-4. 



Fzg. 10. Portion of Fig. 9, enlarged. 



Fig-. II. Frontal cross-section of the right hemisphere and corpora <{ua(l- 

 rigemia of the rat, for comparison with sections figured on Plate V. 



Fig-. 12. Cells from cortex of crus olfactorius at point indicated by fi, Fig. 

 4, (.025 mm. long.) 



F?g. 13. Small area from cortex of ventral surface of hemisphere, in sec- 

 tions passing through the front of the callosum. {C. Fig. 8,) .\ 170. 



Ftg. I4. Portion of cortex from ventral aspect of hemisphere, near median 

 portion of the pyriform lobe at the level of the anterior commissure. (Fig. 8 ii, 

 Plate n.) 



PLATE IL 

 C. L. Herrick. 



Ftg. I. Longitudinal vertical section of anterior p.nuoii "i ikiui-imicic <>i 

 Rabbit. 



Fzg. la. Portion of glomerular layer of olfactory nerve bundle. 



Ftg-. 2. Portion of upper cellular layer of crus olfactorius. 



Fzg. 3. Section through the granular, ganglionic, and gelatinous layers of 

 olfactory lobe. 



Fig-. 4. Horizontal section of anterior part of cerebrum, with ..Ifai tory 

 lobe, Arctomys. 



