Histological Appearances of the Mammalian Pituitary Body 125 



at certain points, especially behind. Great care must be taken not to 

 rupture the thin layer of epithelium which in the cat is continued back- 

 wards from the anterior lobe, to be reflected at the place where the 

 blood-vessels enter the posterior lobe to form a closely fitting investment 

 over the ventral aspect of the latter. Removal of the pituitary from the 

 cranial cavity by raising the brain and dissecting from above is almost 

 invariably followed by rupture of the neck of the posterior lobe. The 

 dura mater should always be- preserved intact without being pulled upon, 

 and the best way to do this is to dissect off the bone from below, disturbing 



^4^lg;Xj^ 



Fiu. 1. — Mesial sagittal section through pituitary body and sella turcica of 

 new-born kitten. (Semi-diagrammatic.) 

 a, optic chiasma ; b, tonRue-like process of pars intermedia ; c, third ventricle ; ff, anterior lobe proper ; 

 e, epithelial cleft ; /, central cavity of posterior lobe ; </, nervous substance of posterior lobe ; h, posterior 

 reflection of epithelium. 



the base of the brain as little as possible. A portion of the brain can 

 then be cut out with the pituitary attached, and the piece trimmed after 

 hardenino-. 



Morphology. 



The relations of the anterior and posterior lobes of the pituitary to 

 one another, and to their immediate surroundings, can be most readih- 

 appreciated by reference to the comparatively simple pituitary of the 

 new-born kitten. Fig. 1 is a diagram of a mesial sagittal section throuo-h 

 the pituitary and sella turcica of a new-born kitten. The infundibulum 

 cerebri is a continuation of the brain backwards and slightl}' down- 

 wards, and consists of a comparatively thin wall oi brain substance 



