Studies on the Endocriuo Glands 



349 



aljundiiiit coarse chromatin <^ranules. They stain for the most part 

 very deeply with Iwematoxylin. Between the vesicles are seen consider- 

 able j^roups of epithelium cells. In portions of the walls of the vesicles 

 the epithelium ct-lls have proliferated so as to cause a thickenintj and 

 projection of the epithelium into the cavity. Here and there are 

 mitotic Hj^ures. 



Parathyroids. — The removal of the parathyroids was contirmed 

 by microscopical examination of the portions of the gland extiipated. 





Fig. 2. — Part of tl\e gland which was left after removal of the larger portion. 



The animal was killed sixty-three days after removal. Alicrophotograph ; mag- 

 nified 80 diameters. Celloidin embedded, hasnmtoxylin-eosin jireparatioii. 



The vesicles are irregular in shape ; many of them are tubular, 'i'hey vary much 

 in size. The lining epithelium is thicker than normal There is a remarkable 

 amount of intervesicular tissue which seems to be com])osed of the same cells as 

 those whic h line the vesicles. The colloiil within the vesicles has a thin appearance, 

 and stains only faintly with haeraatoxylin. 



The remaining left internal parathyroid was examined after the animal 

 had been killed, and showed no alteration from normal. 



Summary. 



The remaining portion of thyroid after partial thyroidectomy under- 

 goes proliferation of its epithelial cells and the vesicles show marked 

 polymorphism. There is little or no change in the parathyroid. 



Partial parathyroidectomy causes no apparent changes in the remain- 

 ing parathyroid tissue nor in the thyroid. 



