io8 



EQUINE ANATOMY. 



Lobes. 



The olfactory or ethmoid is a detached portion lying below and 

 in front of the anterior portion of the cerebrum. It arises by two 



FIG. 16. 



GENERAL VIEW OF THE BRAIN; LOWER SURFACE. 



i, Olfactory lobe; 2, Cavity of the olfactory lobe; 3, External root of the olfactory 

 lobe; 4, 5, Cerebral hemispheres; 6, Cerebellum; 7, Optic chiasma, or commis- 

 sure; 8, Pituitary gland; 9, Optic nerves; 10, Tuber cinereum; n, Cms cerebri; 

 12, Third cranial nerve; 13, Fourth nerve; 14, Pons Varolii; 15, Fifth nerve; 16, 

 Sixth nerve; 17, Seventh and eighth nerves; 18, Medulla pblongata, the number 

 being placed on the olivary body; 19, Anterior pyramid; 20, Roots of ninth, 

 tenth, and eleventh nerves; 21, Twelfth nerve. 



roots, one from the outside of the mastoid lobe and one near the 

 optic chiasm. The enlargement or bulb lies on the ethmoidal 

 fossa, and has an internal cavity communicating with the lateral 

 ventricle (see First Nerve). 



