Thyroid Weight and Function as Influenced by Environmental Temperature

THE possibility of a relationship between thyroid weight and function has been investigated by several workers. Because the data obtained suggest a positive correlation between weight and function to some observers and a negative correlation to others, the question might be raised whether any relationship exists at all. Data recently obtained in this laboratory, as a result of a study of the effects of environmental temperature on the endocrine glands, may serve to clarify this question. REVIEW OF THE LITERATURE Although Barelli (1932) concluded that, in contrast to that of mammals, the thyroid of birds does not act in heat regulation and Lee and Lee (1937) found that thyroidectomized geese adapted to a cold environment, it is generally accepted that the thyroid plays an important role in regulating the metabolic processes. When the chick is subjected to a cold environment, it responds by increasing oxygen consumption (Kleiber and Dougherty, 1934, . . .