The Development of the Mammalian Pituitary Body 179 



consists of a narrow canal lined by ependyma cells passing backwards from 

 the wider lumen of the cavity of the body of the posterior lobe to meet 

 with the fold of buccal mucous membrane and pass through it into its 

 cleft. The ependyma cells cease where the canal meets epithelium, and the 









Fig. 9.-3resial sagittal section tlirougli postero-superior angle of the 

 posterior lobe of the pituitary „f a kitten near full time. Drawing 

 from a j)hotograpli. * 



"' ^n? nnL?rii'j.^"?' ''^w' ' ''' r,"*''" '""^'^y °f posterior lobe ; c, nervous substance 

 of posterior lobe ; d, caiml from cavity of posterior lobe opening into cleft 



lining of its actual opening into the cleft is formed by the epithelium of 

 the buccal invagination. The opening takes place at a comparatively late 

 stage in development, after the buccal invagination has become separated 

 from its origin by the growth of the sphenoid bone. I have examined many 



