In this the condition of the thyroid gland is only part of the morbid phenomena. The eyeballs are prominent, the heart liable to excited action, and the thyroid gland is enlarged and vascular. The disease seems to be due to a lesion of the vaso-motor nervous system, and the thyroid gland shows after death no constant lesion. It has been found hyper-trophied, or abnormally vascular or cystic, but also in many cases normal. The suggestion has been made that the disease is due to a hypertrophy of the thyroid gland whose excessive secretion leads to the symptoms, but this view has not been confirmed.