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ANATOMY OF 



being united in the centre, and their commissure being termed me- 

 solobe or corpus callosum. It has a longitudinal depression, called 

 raphe or suture. When still more is removed horizontally, a 

 large cavity appears immediately on each side of the centre, 

 called the lateral ventricle : which runs forwards into the anterior 

 lobe, making an anterior cornu ; backwards into the posterior 

 lobe, making a posterior cornu, ending like a finger, and thus 

 forming what is called a digital cavity ; and downwards into the 

 middle lobe, making an inferior cornu. A septum exists between 

 the two lateral ventricles, called septum lucidum, with a little space 

 called the Jifth ventricle between the two layers of which it con- 

 sists. In each lateral ventricle is a white mass, called thalamus 



Horizontal view of the cerebrum, sufficient being cut away to exhibit, 1,1, the 

 great mass of white fibrous substance, surrounded on the surface by the grey 

 pulp. 2, 2. Corpora striata, and lateral ventricles. 3. Septum lucidum. 4. Fifth 

 ventricle. 5, 5. Semicircular band separating the corpora striata from the thalami 

 optici, upon which lie, 6, 6, the plexus choroides. 7, 7. Fornix. 8, 8. Its posterior 

 pillars, turning round to face the fimbriated bodies. 9, 9. Part where the superior 

 part of the lateral ventricles communicates with the inferior, which is not seen. 

 10, 10. Ergot. 11,11. The posterior part or digital extremity of the lateral ven- 

 tricles. 



