58 DISSECTION OF THE CAT 



ID. The Lamina Cinerea lies just anterior to the 

 optic chiasma. It is a thin membrane, connect- 

 ing the optic chiasma and corpus callosum, and 

 enclosing a cavity in the brain known as the third 

 ventricle. (Plate VII., c.) 



1 1. The Pituitary Body is situated at the end of a 

 conical prolongation of the ventral surface of the 

 brain just posterior to the chiasma. In most cases 

 it is torn off in removing the brain from the skull, 

 leaving nothing but a hollow stalk. (Plate VII., 

 A and c.) 



12. The Infundibulum is the hollow conical pro- 

 jection which forms the stalk of the pituitary body. 

 The cavity of the infundibulum is continuous with 

 the third ventricle. (Plate VII., c.) 



13. The Tuber Cinereum is a slight prominence, 

 from which projects the infundibulum. (Plate 



VII., A.) 



14. The Corpora Albicantia are two small, rounded 

 elevations, just posterior to the tuber cinereum. 

 (Plate VII., A.) 



15. The Crura Cerebri are two thick bands of 

 fibres which diverge on either side of the corpora 

 albicantia, and pass dorsal to the optic tracts. 

 (Plate VII., A.) 



16. The third pair of cranial nerves, the Oculo- 

 motor, emerge in the mid-ventral line, posterior to 

 the corpora albicantia, in the angle between the 

 diverging crura cerebri. (Plate VII., a.) 



1 7. The fourth pair of cranial nerves, the Pathetic, 



