The attention of an observer is attracted to diseases of the endocrine system by unmistakable abnormality of development in young individuals, by a group of signs of variable definiteness or by autopsy observations. Except in certain gigantic states and sexual dystrophies, changes in anatomy and physiology of the pituitary body do not express themselves in a clear-cut manner. Acromegalic and genital alterations, while fairly clear in the human being, are not by any means so readily determined in the lower animals. This is especially true of wild varieties. In a reasonably complete review of the literature I did not discover a satisfactory case of pituitary disease in wild animals. There are numerous references in the literature to inflammation, strumas and tumors in the domestic animals, and there is a considerable volume of writing about the state of the hypophysis during pregnancy and hibernation. However, the relationship of pathologic to clinical