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INTRODUCTORY.RECENT complete researches by Herring (3) and by Hoskins (4) have been directed to investigation of the effects produced on endocrine and other organs by administration of small amounts of thyroid gland.Both these authors examined the organs concerned during thyroid administration, when it may be concluded that the effects would be most marked.The technique of their experiments differs in certain details; mainly, however, in the size and the frequency of the doses. Among the results obtained by them are -hypertrophy of the heart, liver, kidneys, and suprarenals.Kuriyama (7), who repeated some of Herring's experiments, concludes that the weight of the suprarenals of medium-sized albino rats is not affected by thyroid feeding of either short duration with large doses or long duration with small doses.This result, opposed to those of Herring and of Hoskins, merits further analysis.Kuriyama in each of his three tables groups together male and female rats of greatly diverse weights (69'2 to 304-8 grm.), and from these obtains average figures which are compared. As it is well known (Donaldson (2)) that the suprarenals of rats over 40-50 days of age are, for either animals of equal length or equal weight, greater in the female than in the male, this method of averaging results is not without serious objection.No data are given by Kuriyama as to the body-length of his rats, and in view of the extreme variations in weight caused by different diet in animals of the same length, it would appear that more trustworthy comparisons could have been made had these been given.If the weights of the suprarenals of Kuuriyama's normal rats be

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