THE EFFECT OF HYPERTHYROIDI-SATION ON THE PLUMAGE OF CARNIVOROUS BIRDS.

During the latter years a considerable amount of investigating work has been done on the influence of fresh thyroid gland and preparations of it on the growth and development of the feathers of birds. But all these researches with a few exceptions refer to granivorous birds, principally domestic fowls. The literature, however, on the influence of the thyroid gland on the organism of carnivorous birds is but very scanty. It is to contribute to the eludication of this question that the present investigations were undertaken.