Studies on the Endocrine (J lands 311 



injected subcutaneously with thyroid decoction, received the extract of 

 3 grni. of dry ox-thyroid per diem. In this case again, on the fourtli day, 

 the animal was found to be inactive, with greatly decreased appetite. 

 There was, however, no diarrho-a. Nevertheless, the animal died on the 

 niirht of the fourth dav. Po.st-mortem No. 1 showed a con.siderable 

 amount of hyperajmia of the intestines after death, and the contents of 

 the large intestine were watery. The other two rabbits exhibited nothing 

 special. No microscopic examination was made of any of these animals, 

 since they had been dead several hours before the organs could be fixed. 



Guinea-pig. — Two full-grown males, weighing respectively 450 grrn. 

 and 500 grm., were fed with oats and cabbages during a week. After 

 that period the pres.sed-out juice of 3 grm. of fresh sheep-thyroid was 

 smeared on to the cabbage, which they ate as usual. (It was much more 

 difficult to get rabbits to eat cal^bage which had been smeared with 

 thyroid juice.) One of the animals was found dead after four days, and 

 the other after five days. In these cases also there was no microscopic 

 examination of the pancreas. 



Effect of Feeding Birds with Thyroid. 



For this .series of experiments specimen.s of the domestic fowl at various 

 ages were employed. They were fed witli a mixture of maize and broken- 

 up rusks. 



It may be well first to give a short description of the normal 

 pancreas of the bird. The pancreas of the domestic fowl shows 

 certain peculiarities. As compared with the rat's pancreas the 

 alveoli are generally smaller, as are also the alveolar cells. 

 The outer zone of each cell is narrow' ; it stains deeply with 

 h«matox3'lin. ]\Iost of the nuclei are small (3'7/li), but a certain 

 number measure 5fi. The chromatin granules in the nuclei are 

 fine. The nuclei are as usual placed near the base of the cells ; they 

 are for the most part only feebly stained by hjematoxylin. Both 

 nuclei and nucleoli are stained blue by Mallory. Although sections 

 from a number of glands from normal animals were searched, only 

 once could a mitotic fiofure be found. The cells do not show vacuo- 

 lation. The zymogen granules vary considerably in amount. In 

 some alveoli the cells are full of them, but there is no marked dis- 

 tinction between inner and outer zones as in mammals. In other 

 alveoli the zymogen granules are few, and are scattered within the 

 cytoplasm. As has been noted in the rat, cat, and dog, zymogen 

 granules are especially plentiful in the alveoli which immediately 

 surround the islets : they decrease gradually in amount as the alveoli 

 become more removed from those structures. Under a low power 

 this produces in Mallory preparations the eftect of red patches 

 surrounding the i.slets. 



The islets are compact in appearance. Their cells contain very fine 

 granules, red stained by Mallory, scattered uniformly in the cytoplasm. 

 The nuclei measure S'7 fj., and contain fine chromatin granules. 



