318 Studies on the Endocrine Glands 



DESCRIPTION OF PLATES I. AND II. 



Plate I. 



A. Section of pancreas of normal male rat. Magnified 400 diameters. Stained 

 by Muir's method. 



B. Section of pancreas of male rat fed during seven days before being killed 

 with addition of I'O grm. dried ox- thyroid to its ordinary diet. Magnified 400 

 diameters. Stained by Muir's method. 



A number of mitoses are visible in this section^ whereas none are to be seen in 

 the normal pancreas. The zymogen is greatly reduced in amount. 



Plate II. 



Section of an outlying portion of pancreas of male rat, fed with addition to its 

 ordinary food of 1"0 grm. dried ox-thyroid during one week, followed by a few days' 

 intermission, and then by another week of thyroid feeding. Magnified 600 diameters. 

 Muir's stain. Only one mitosis is seen in the field. The nuclei are very variable 

 in size (in the normal pancreas they are very uniform) ; some are very large ; for 

 the most part they contain large red-tinged nucleoli. The cells also vary much in 

 size : they have lost the regular arrangement into alveoli, and are separated by con- 

 siderable spaces in which leucocytes and spindle-shaped cells (? connective-tissue 

 cells) are visible. The zymogen granules are greatly reduced in amount. 



