Structure of the Pituitary 



79 



the cells of an ordinary secreting gland around the lumen of the alveolus. 

 In some animals all the cells of the pars anterior are set like a columnar 

 epithelium round blood-sinuses this is strikingly shown in Elasmobranch 

 fishes such as the skate. In the tortoise columnar cells surround closed 

 vesicles containing a colloid material. The basiphil cells are, when present, 

 mostly found near the periphery of the trabecular masses. In pregnancy 



3H 



ta.*V'fcl 



t 4 



d 



Flo. 50. Section of pituitary of cat at intraglandular cleft (b), showing on the 

 left side (a) the highly vascular pars anterior, and on the right side of 

 the cleft the pars intermedia (c), in which several vesicles are seen, and 

 which abuts on the pars nervosa (d). Magnified 200 diameters. ( Figs. 50, 

 52, and 54 are from sections prepared for me by Dr M. Kojima. ) 



large, finely granular oxyphil cells are observed in unusual number (Erdheim 

 and Stumm) : these cells have been designated pregnancy cells. Oxyphil 

 cells are also unusually abundant in the enlarged gland of acromegalic 

 subjects, where they form adenoma-like masses. Most of the cells also 

 contain numerous fine fatty globules. 



There is a small amount of reticular connective tissue between the cells. 

 A few nerves have been traced into the pars anterior from the pars nervosa. 



Under certain circumstances in man and mammals, especially in cases 

 of thyroid absence or insufficiency, a product of secretion of the anterior 



