374 



PHYSIOLOGY 



of nervous matter, the lamina cinerea,at the upper border of which, project- 

 ing slightly into the ventricle, is a strand of white fibres connecting the an- 

 terior parts of the two optic thalami and known as the anterior commissure. 

 The roof of the third ventricle is formed entirely of epithelium, the ependyma, 



, - - ^. .-.-. 



Olfactory 

 tract 



Corpus callosum 



Lateral ventricle 



Nucleus caudatus 



Internal capsule 



Thalamus 



Nucleus lentlformis 



Anterior commissure 



ftolllculus superior 

 Inferior brachium 



Colllculus Inferior 

 4th nerve 



Trigonum lemn 

 5th Tie 

 Brachium conjunctlvum 



8th nerve 



Restlform body 



9th nerve 



10th nerve 



Olive 



12tU lit T\r 



I i'. I MI. Right lateral aspect of brain stem, with a part of the cerebrum. 

 (J. SYMINGTON.) 



along the upper surface of which is the layer of pia mater, the velum inter- 

 positum. The roof is invaginated into the cavity by two delicate vascular 

 fringes, the choroid plexuses. At the back part of the roof is attached the 

 stalk of the pineal body, and behind this 'stalk, between the anterior parts 

 of the anterior corpora quadrigemina, is a small space known as the trigonum 

 habenulce, which contains a well-marked collection of nerve cells known as the 

 ganglion habenulce. The lateral walls are formed entirely by the optic 

 thalami. The upper surface of the optic thalamus looks into the lateral 

 ventricle of the cerebral hemispheres, from which it is separated by the 

 velum interposition and by the ependyma, the epithelium completing the 

 inferior wall of the lateral ventricle in this region. It consists of three 



Optic nerve 

 Ant. perforated space 

 Optic tract 

 3rd nerve 

 Corpus mammlllare 



