Does the Administration of the Anterior Lobe of the Hypophysis to the Tadpole Produce an Effect Similar to That Obtained From Thyroid Feeding*

In a recent paper Hoskins and Hoskins (1920) have advanced evidence showing that the feeding of the anterior lobe of. the pituitary gives an effect similar to, and perhaps even identical with, that which is characteristic for the administration of thyroid gland. This is the most convincing evidence which to our knowledge has been advanced in support of the hypothesis that the pituitary can act vicariously for the thyroid. Hoskins and Hoskins, in brief, showed that a preparation of the anterior lobe when fed to the tadpole gave the typical responses resulting from thyroid administration, i. e. cutaneous and mouth changes, leg growth, tail absorption, and other changes leading to metamorphosis. In the normal unoperated tadpole metamorphosis was prematurely inaugurated or greatly accelerated; in the thyroidectomized tadpole similar changes were induced, though, as is well known, they would never have otherwise appeared in these thyroidless specimens.