Studies ou tlie Eudociiue U lands 295 



continued until the animals were killed, in one case twenty-five days 

 after the administration had ceased. (Rat No. 03 was killed seven days, 

 rat No. 62 twenty-five days, after the second administration of iodi<le 

 had ceased.) 



Post-mortem.— Rats Nos. 00 and 01 showed slight congestion of the 

 intestines. In the others there was nothing noticeable. 



Pancreas. — On microscopic examination of the pancreas of all 

 four animals con.sidernble variation is seen in the .size of the alveoli 

 and of their cells (fig. 17). There are many more small alveoli than 



\*< 



Fig. 17.— Section of pancreas of rat (male) fed with an addition to its ordinary diet 

 of 0"1 grm. of sodium iodide per diem during five days. Microphotograph ; 

 magnified 400 diameters. H;t'matoxylin preparation. 



The appearances are similar to those of thyroid feeding. Tlie alveolar cells 

 vary remarkably in size, as do their nuclei. The latter contain abundance 

 of coarse chromatin granules and are for the most part deeply stained with 

 hsematoxylin. Several of the cells exhibit mitosis. Some have abundance of 

 zymogen, others only a little. 



in the normal condition, and there is a general increase in size of the 

 cell-nuclei, although a certain number remain small. The nuclei are 

 deeply stained by hematoxylin, and contain abundant coarse chromatin 

 granules with large nucleoli ; a few which are less deeply stained 

 have only fine chromatin granules. Many of the nucleoli are stained 

 red by Mallory. The zymogen granules are somewhat fewer than 

 normal (fig. 18). A few cells contain vacuoles. In rats Nos. 60 

 and 61 a certain number of the cells show mitotic figures and a few 

 contain vacuoles, but in rats Nos. 62 and 63 neither mitosis nor 

 vacuolation is to be found. 



(c) Administration of Sodium Iodide to Rats which had been 

 previously thyroidectomised. — In this experiment four thyroid- 

 ectomised rats were, after recovering from the operation, fed during five 



