446 INANITION AND MALNUTRITION 



islets of crowded epithelial cells, usually syncytial, and chiefly of the "principal" 

 cell type. 



In 7 athreptic infants, Harvier ('09) found the parathyroid glands normal 

 in 5; but in 2 cases there was somewhat marked sclerosis, with the parenchyma 

 cells in "pseudo-vesicular" groups, some containing colloid. In one case, 

 numerous small hemorrhages occurred in the inferior parathyroids. 



Helmholz ('09) likewise found the changes in the parathyroids in 6 atrophic 

 infants less extensive than those described by Thompson. The glands appeared 

 decreased in size, but microscopically unchanged, except a slight increase in 

 connective tissue along the blood-vessels. "In dem Parenchyma waren keine 

 Unterschiede von den normalen zu erkennen." 



Mattei ('14) found the parathyroids of athreptic infants notably decreased 

 in volume with marked general fibrosis (sclerosis), and variable cytoplasmic 

 changes in the parenchyma cells. The results of the earlier investigations on 

 the parathyroid in atrophic infants were summarized by Nobecourt ('16). 



Animals. — Alagna ('08) described a cystic condition of the parathyroids in 

 a dog killed after a long fasting period, but this condition was probably not due 

 to the inanition. 



In the hibernating gopher (Spermophilus tridecemlineatus), according to 

 Mann ('16), "The very slight and inconstant changes noted in the parathyroids 

 do not warrant any positive conclusion." 



Jackson ('16) found in albino rats that: 



"The parathyroid glands appear to be relatively larger in the female. 

 They apparently belong to that group of organs in which growth persists in 

 young rats, even when held at maintenance (constant body weight) by under- 

 feeding. In adult rats during acute and chronic inanition, the reduction in the 

 size of the parathyroids is nearly proportional to that of the body as a whole. 



"In histological structure, the parathyroid gland is relatively more resistant 

 than the thyroid to inanition. The changes in the structure of the epithelial 

 cells are somewhat similar to those described for the thyroid, though in general 

 less marked. In many of the cells there is apparently no decrease in the average 

 size, but some (especially those degenerated) show marked shrinkage. The 

 nuclei may remain nearly normal in size and structure, though usually exhibiting 

 various stages of (rarely) karyolysis or (more frequently) karyopycnosis. No 

 cell-division is found. The cytoplasm may be either somewhat reduced in 

 amount, sometimes deeply-staining ('oxyphile'), or may remain nearly normal 

 in volume, with marked vacuolization ('hydropic degeneration')- The stroma 

 may remain normal in amount, but is occasionally increased in volume by 

 infiltration of ground substance." 



Among the various types of partial inanition, the most conspicuous changes 

 in the parathyroids have been found during rickets. Erdheim ('14) described 

 a marked enlargement of the parathyroid glands in rats with spontaneous 

 rickets. In human rickets, Ritter ('20) found that hypertrophy of the para- 

 thyroids appears less common in the early cases than in those of long standing, 

 in which perhaps recuperation is beginning. Instead of the normal light 

 "Hauptzellen," the parathyroid cells are of the dark cell type, with frequent 



