264 Kojima 



(b) Effects of ParathjToidectomy on the Rat's Pancreas. 



No. 1 rat of B group. Parathyroidectomised thirty-five days before 

 death. Weight 295 grm. 



There is nothing particular to record post-mortem. The thyroid gland 

 is perhaps somewhat paler in colour than normal. The intestines and other 

 organs seem to be normal. 



Pancreas. — The nuclei of the alveolar cells measure about bu.; a 

 few are a little larger (6'2/>i). These last contain distinctly outlined 

 nucleoli, whilst most of the others have uniform!}' scattered chromatin 

 granules, and the nucleoli are not distinct. When the nucleolus is 

 marked there seems to be a clear space around it in the nucleus, 

 the particles of chromatin being for the most part arranged near 

 the periphery. In the Mallory preparations the nucleoli are fre- 

 quently stained red, but sometimes faintly blue : the rest of the 

 nucleus takes the blue colour. Speaking generally, the alveolar 

 cells are similar to those of the control, but the cytoplasm has a less 

 compact appearance and contains fewer zymogen granules, the outer 

 zone being a little thicker in proportion to the inner. Some alveoli 

 show vacuoles — but these have not the sharp outlines and conspicuous 

 appearance of the vacuoles met with in the thyroid-fed animal (p. 267). 



The islets of Langerhans have a somewhat looser texture than 

 usual, but there is a certain amount of difference in this respect 

 even in normal animals. No difference from the normal can be 

 determined in the centro -acinar cells, nor in the connective tissue of 

 the gland. 



Two parathj-roidectomised rats, which had been fed during the whole 

 time with ground rusks and water alone (except for thyroid additions during 

 the second week and parathyroid additions during the third week), were 

 killed on May 15, ninety-seven days after the operation. These rats are 

 respectively Nos. 4 and 5 of group B. The weight of No. 4 was 120 grm. : 

 of No. 5, 110 grm. The oriofinal weio^hts were 125 grm. and 135 grm. 

 respectively. Post-mortem there is nothing noticeable. 



Pancreas. — The alveoli are moderate!}^ large; their cells are for 

 the most part large, but there are many smaller cells, the nuclei of 

 which are relatively small and situated close to one another, as if the 

 result of division. The diameter of the nuclei varies between 5/x 

 and 6"2^, but some are considerably larger. Nucleoli are distinct 

 in some nuclei, but most nuclei only contain coarse chromatin 

 granules scattered uniformly. There is no sign of mitosis, but there 

 is a good deal of vacuolation in the cytoplasm in some places, although 

 not the characteristic vacuolation caused by thyroid feeding. The 

 islets of Langerhans appear normal. 



(c) Effects of Thyroidectomy. 



No. 1 rat of C group. Weight 190 grm. Killed thirty -four days after 

 thyroidectomy. 



