490 



PHYSIOLOGY 



CHAP. 



Viewed from above the optic thalami are two large oval masses 

 of grey matter, which are covered by a thin sheet of white fibres. 

 At the anterior end a mass known as the tuberculum anterius 

 projects into the lateral ventricle, and is covered "with the 



Fio. 245. View from above of third ventricle and part of the lateral ventricles. (Henle.) The 

 brain has been sliced horizontally immediately below the corpus callosum, and the fornix and 

 velum interpositum have been removed. Tho, thalamus options ; Ts, its anterior tubercle ; 

 Pi;, pulvinar ; Com, middle commissure stretching between the two optic thalami across middle 

 of third ventricle ; Cf, columns of fornix ; Cn, pineal gland projecting downwards and 

 backwards between superior corpora quadrigemina ; St, stria terminalis ; Cs, nucleus caudatus 

 of corpus striatum ; Vsl, ventricle of septum lucidum ; CeZ 2 , section of genu of corpus callosum ; 

 Pen, pineal peduncle ; Tfo, pineal stria ; Cop, posterior commissure. 



epithelium that lines this cavity. At the posterior and mesial 

 end a still more conspicuous prominence, known as the pulvinar, 

 extends over the quadrigemiual bodies and partially covers them 

 (Fig- 245). 



