Studies on the Endocrine Glands 



313 



no diarrlvi-a. At the end of the time the weights were respectively 

 450 o-rin. and 372 "Tin. There was nothinir to be observed on post-mortem 

 examination. 



For investigating the effect of injection of thyroid, a full-grown hen, 

 weighintr ^00 frm., after having been fed with maize for a week, was in- 

 jected subcutaneously each day with a decoction made from 5 grm. of 

 dry o.\-thyroid. On the third day the animal appeared inactive, and took 

 very little food. The next UKirning it was found dead. Nothing could be 

 noticed on post-mortem examination. 



'K..-fW 



Fig. 29. — Section of pancreas of cock fed with an addition to its ordinary 

 food of 4'5 grm. of dry ox-thyroid per diem during live days. Micro- 

 photograph ; magnified 500 diameters. Mallorj-'s stain. 



Notice the more compact appearance of the gland owing to the smaller 

 size of the alveolar cells. There is marked diminution in the amount of 

 zymogen, the granules of which when present are not stained nearly as 

 darkly as in the normal pancreas. In many of the cells they appear 

 merely as dark points scattered in the cytoplasm. 



Another bird, also a full-grown hen, weighing 950 grm., was then in- 

 jected subcutaneously during five days with a decoction made from 7 grm. 

 of dry ox-th3^roid. The appetite was only slightly affected ; there was no 

 diarrhcea. At the end of the experiment the bird was killed ; its weight 

 was then the same as at the beginning. 



Pancreas. — Comparing the pancreas of the thyroid-fed and 

 thyroid-injected animals with that of the normal animal (figs. 28 and 

 29), it is to be noted that the size of the alveolar cells shows little or 

 no difference ; this is also true for their nuclei. Some of the nuclei 

 have an irregular appearance suggesting mitosis, but we have been 

 unable to assure ourselves that this is a karyokinetic appearance. No 

 vacuoles are seen in the cells. There is a remarkable diminution in 



