Studies on the Endocrine Glands 



287 



Ox-Thyroid.— In this ca.se some of the rats of the C and D groups 

 had diarrlid'a from the third day. The appetite of the animals belonging 

 to D group .seemed to be atiected niore than the rest. As with the sheep- 

 thyroid, the iodine test was positive in every case. 



Table XI. — Weights of Rats fed with W.\ter-Extract of Sheep-Thyroid 

 AND with the Residue (Boiled and Unboiled). 



Table XII. — Weights of Rats fed with Water-Extract of Ox-Thyroid 



AND WITH THE ReSIDI'E (BoILED ANH UnhOH.ED). 



All the animals were killed on July 29, after five days' thyroid feeding. 

 Post-mortem there was nothing to remark except that the intestines 

 were slightly congested in two of the animals (Nos. 45 and 46). 



Pancreas. — On microscopic examination of the pancreas of the 

 rats belonging to the A groups (Nos. 31, 32, 39, 40) a great varia- 

 tion in the size of the alveolar cells is noticeable. Their nuclei 

 measure from 3'7/a to 7"5/x most being fairly large. They con- 

 tain abundant coarse chromatin granules and comparatively large 

 nucleoli, which in some cases (Nos. 39 and 40) are stained red by 

 Mallory, in others (Nos. 31 and 32) blue. Zymogen granules are 

 scanty. Many of the cells contain small vacuoles. A few exhibit 

 mitoses. 



In those belonging to the B groups (Nos. 33, 34, 41, 42) there are 

 more small cells mingled with the larger cells of the alveoli than 

 in the A groups. Most of the nuclei are large (some were 10/x) ; 

 each of these larcfe nuclei contains a larg^e nucleolus and abundant 

 coarse chromatin granules. They are stained deeply by hasmatoxylin 

 (especially in Nos. 34 and 41). There are also a fair number of small 



VOL. XI., NOS. 3 AND 4. — 1917. 19 



