MILLER — CONTRIBUTIONS FROM ANATOMICAL LABORATORY. 231 



gradually narrows dorso-ventrally until it is finally obliterated. 

 The dorsal wall or roof of the infundibnlnm is very tliin at the 

 base of the pituitary body but increases in thickness as it pro- 

 ceeds posteriorly. 



NERVES. 



I. Olfactory. These are the most prominent pair of nerves. 

 They arise directly from the ventro-lateral margin of the cor- 

 responding hemisphere. A sharp line on the dorsal side shows 

 the place of origin of the nerve, but on the ventral side no sharp 

 line of demarcation is present. On cross section the nerve is 

 oval in shape. 



In pursuing my work several peculiarities were noticed in 

 the branching of the olfactory nerves of the brains studied. In 

 one instance the nerve, a short distance from the olfactory lobe, 

 broke up rapidly into branches, which ran some distance before 

 entering the nasal capsule. This brain is the one used in the 

 model and in the drawings. In another case the right olfactory 

 nerve divided into two branches almost as soon as it left the 

 lobe ; but in most cases the nerve ran some distance before break- 

 ing up into its smaller branches. 



II. Optic. This nerve is very small and fragile. It arises 

 in the ventro-median line of the thalamenccphalon just a little 

 anterior to the posterior ends of the cerebral hemisphere. There 

 are apparently no elevations or tracts at the place of origin of 

 the optic nerve, but it seems to rise in conjunction with its fel- 

 low- from the surface of the brain. The nerve runs obliquely 

 from its place of origin, thus forming an acute angle wutli its 

 fellow, 



///. Oculo-motor. This nerve arises in the lateral median 

 line at the extreme anterior part of the mesencephalom It is 

 very fragile and is nothing but a thread. It is very easily 

 broken, often separating from the brain in dissecting away the 

 meninges of the brain. It runs along the lateral surface of the 

 brain until a short distance past the posterior ends of the cere- 

 bral hemisphere when it turns off obliquely to the muscles of 



