INFLUENCE OF DIET AND IODIDES OPOSSUMS 



61 



tiates an intracellular secretion antecedent in the form of vacuoles 

 containing apparently a dilute solution of a substance, compara- 

 ble to the colloid, but of less density, which stains blue with the 

 wasserblau on a pink-stained protoplasmic background. They 

 show that hyperplastic glands which ordinarily resemble one an- 

 other very closely may nevertheless differ markedly in secretorj^ 

 potential as indicated by the amount of available antecedents in 

 the cells. The results also show by the variability of the degree 

 of hyperplasia, and of the secretory potential, that there are 

 other factors influencing the rate of hyperplasia in these experi- 

 ments, in addition to the dietary condition. The results, how- 

 ever, indicate clearly that hyperplasia of high degree follows 

 these conditions, as in those described in the former paper. 



Table 2 gives the quantitative results as regards the thyroid 

 gland in two animals which, after a period of three weeks on an 



TABLE 2 



unrestricted diet of table scraps, received two drops of syrup of 

 iodide of iron daily, without change in the food. Although the 

 animal which was kept for six weeks on iodides showed a higher 

 degree of hyperplasia than the one kept for three weeks, it is not 

 clear from this experiment whether the iodine checked the 

 hyperplasia or not. The significant feature of this experiment is 

 the enormous increase of colloid in the gland, confirming the 

 former experiments on the opossum, and those of Marine on the 

 dog as to the possibility of reverting the hyperplastic gland to the 

 colloid type by iodine. 



Table 3 represents three animals in which an unrestricted diet 

 of table scraps was coupled with a daily dose of two drops of syrup 

 of iodide of iron. The results show a degree of hyperplasia, less 

 in degree than in the corresponding controls, but nevertheless 



