EFFECTS ON THE THYROID AND PARATHYROID GLANDS 447 



hyperemia and fibrosis, sometimes also edema. Luce ('23) found that in young 

 rats fed on calcium-deficient diet there is a progressive enlargement of the 

 parathyroid glands, which is due to hyperplasia (not hypertrophy) of the cells. 

 Parathyroid hyperplasia sometimes occurred also on diets deficient in vitamin 

 A in young rats, though not in adults. 



In infantile beriberi, Andrews ('12) found but slight changes in the para- 

 thyroids, aside from congestion. Findlay ('21) similarly observed normal 

 appearance of the parathyroids in pigeons and fowls with beriberi, although 

 the postbranchial body had undergone slight atrophy. McCarrison ('21) also 

 found no marked change in the parathyroids of polyneuritic pigeons, unless 

 complicated by infections, in which case congestion and cell necrosis occurred 

 (as in the thyroid gland) . In 3 monkeys on a diet of autoclaved rice and butter, 

 the parathyroids showed intense congestion and in one case hemorrhagic infil- 

 tration. When onion was added to the diet (either with or without the butter) 

 the parathyroids appeared normal. 



In two cases of infantile scurvy, Ritter ('20) found the parathyroids normal 

 in microscopic appearance and microscopic structure. 



