276 Kojima 



There are a certain number of large round cells with a clear, 

 non-stained protoplasm and a comparatively small nucleus deeply 

 stained by haamatoxylin, whilst other enlarged alveolar cells show 

 typical mitoses. Such cells are, however, far fewer than in the 

 animals with which we were dealing in Series 1, which were fed 

 with 1 grm. of dry ox-thyroid. The zymogen is throughout much 

 more scanty than normal. Many cells have large vacuoles in their 



Fig. 13.— Section from pancreas of rat (male) fed with an addition to its ordinary diet 

 of 4 grm. of fresh sheep-thyroid per diem during four days. Microphotograph ; 

 magnified 400 diameters. Haematoxylin preparation. 



Many of the alveolar cells show large vacuoles. The outer zone of the cells is 

 relatively thick. It is more deeply stained by hiematoxylin than the inner zone. 

 The zymogen is considerably diminished in amount, es])ecial]y in the cells which 

 contain large vacuoles. The nuclei are large and very deeply stained. 



cytoplasm (figs. 12, 18), mainly in the inner zone. The islets of 

 Langerhans appear to have undergone no change. 



Summary. — There is no distinct difference produced by thyroid feeding 

 in the pancreas of the different sexes. All the usual effects of thyroid 

 feeding are well seen in this series, in which fresh sheep-thyroid was 

 employed in place of the dry ox-thyroid. There are, however, fewer 

 mitoses than in the ox-thyroid fed animals, but, on the other hand, more 

 pronounced vacuolation of the cells (this appeared most marked in females) 

 and rather greater diminution in their zymogen contents. 



Effect of Thyroid Feeding on Body-weight in Different Sexes. 



The following table shows the weights at different periods as well as 

 those of control groups : — 



