The occurrence of hereditary premature senescence in a family of pure bred Belgian hares belonging to a rabbit-breeding colony organized for the investigation of constitutional problems, has been described. Representatives of 20 generations of the complex have been studied. The condition was a degeneration of variable degrees of severity and two principal forms were recognized, the acute and the chronic, the chronic being the more frequent. The chronic form has now been described in terms of the principal local or external manifestations; that is, degeneration of the coat and skin, lesions of the eyes and feet, and reproductive abnormalities, and of the general deterioration which in severe cases pursued a progressive course characterized by muscle wasting, fat reduction, emaciation, weakness, and death. The acute form will be described in the next paper (2).

This content is only available as a PDF.