FURTHER EXPERIMENTS UPON THE EFFECTS OF EXTIRPATION OF THE THYMUS IN RATS, WITH SPECIAL REFERENCE TO THE ALLEGED PRODUCTION OF RACHITIC LESIONS.

Rachitic changes in the bones and teeth occur in young albino rats as the result of spontaneous disease, possibly of infective origin. This disease is often, but not always, accompanied by an arrest of growth and malnutrition. There is no valid reason for attributing such lesions to the loss of thymic function. In some of the rats showing the disease, an unusual number of mitoses were found in the parathyroid glands, but no evidence of injury to these structures. It has not been found possible to confirm the statements of Klose and Magnini as to the fatal effects of complete thymus extirpation in rats.