抄録
Pinealectomized rats seemed to become more sensitive to ultraviolet rays, as far as the grade of photosensitivity was measured through observations of erythematous change of the skin occurring after 90-120 minutes' irradiation. This result, increased ultraviolet sensitivity of rat due to pinealectomy, may be an important evidence suggesting the role of the pineal organ itself as a photoreceptor and/or a source of an agent regulating photosensitivity also in the mammals, which fact has long been postulated with considerable reasonability from the view points of comparative anatomy and endocrinology, but lacking a definite proof.
