134 



Herri 



ring 



has more recently confirmed Saint-Remy's views. He distinguishes three 

 main forms showing transitional stages. The small, poorly granular cell 

 is the young form, while the large, deeply-staining granular cell marks 

 the acme of functional development. A third variety is the large cell 

 devoid of granules, which he regards as a cell the function of which is 

 temporarily or permanently interrupted. Benda pointed out that there is 

 no evidence of any of the cells being the products of degenerative changes 

 as supposed by Schonemann, and further that the granules bear no 





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Fig. 6. — Mesial sagittal section through part of the pituitary body of an adult cat. 



a, anterior lobe showing different forms of epithelial cells : the blood channels are collapsed and 

 their position indicated only by endothelial cells; 6, epithelial cleft separating anterior from 

 posterior lobe; c, epithelial iuvestmeut of posterior lobe — " Epithelsaum " of Lothringer; 

 d, nervous substance of posterior lobe. 



relation to the formation of colloid material. He believes that the granules 

 break down into a secretion which passes directly into the blood-vessels by 

 diffusion through their thin walls. 



My own observations are to a large extent confirmatory of the views 

 expressed by Benda. In the anterior lobe of the cat's pituitary there 

 exist three main varieties of cells : a small polygonal cell with large nucleus 

 and little protoplasm, containing few or no granules ; a larger cell with 

 similar nucleus and protoplasm, which may be clear, but frequently shows 

 a diffuse arrangement of fine granules ; and, lastly, cells which are full of 

 deeply-staining material. The latter kind of cell is sometimes smaller than 

 the diffusely granular form (cf. fig. 7), but this is not always the case, and 



