34} ON THE ANATOMY OF THE 



convolutions of the brain are externally less strongly 

 marked ; the pia mater seems less vascular but pe- 

 netrates deeper into the cerebrum than in the hu- 

 man subject ; the protuberances lodged in the su- 

 perior fossae of the occipital bone are remarkably 

 pointed ; the cerebellum bears a larger proportion 

 to the cerebrum ; and the latter appears somewhat 

 less deep. The veins supplying the great longitu- 

 dinal sinus run from behind forward, as in man. 



In examining the internal parts of the brain, the 

 usual horizontal sections were employed. 



The cineritious matter near the top of the brain, 

 bears rather a larger proportion to the medullary 

 than in the human body ; because the fissures be- 

 tween the convolutions are deeper in this animal : 

 but the proportional quantity of medullary sub- 

 stance becomes greater on penetrating to the level 

 of the corpus callosum, the centre of which is only 

 0.9 inch below the upper surface of the brain. The 

 lateral ventricles do not essentially differ from what 

 is found in man. The corpora striata are less pro- 

 minent and smaller, as is the choroid plexus. The 

 fornix, with its pillars, the septum lucidum, and 

 the (corpora quadrigemina, are exactly like the cor- 

 responding parts in man. The pineal gland is re- 

 markably large, but is similarly situated behind the 

 posterior commissure of the cerebrum. It had no 

 gritty substance in it ; a circumstance often noticed 

 in the human brain. The glandula pituitaria and 

 infundibulum are very well marked. 



