In 1926, Weil in collaboration with one of us (Keschner1) described a case of dystrophia myotonica characterized histopathologically by selective involvement of the vegetative nervous system. Since then only one other case with necropsy observations has been reported (Guillain, Bertrand and Rouquès, 19322). The object of this contribution is to record two additional cases of this disease occurring in a brother and sister, with the necropsy observations in one (brother). REPORT OF CASES Case 1. —L. P., a man, single, aged 40, born in Russia, a newsdealer, was admitted to the Montefiore Hospital on July 26, 1923, complaining of weakness of the lower extremities and general fatigue. His father died at the age of 77 of "stomach trouble;" the mother died of some unknown cause at the same age. Two sisters died at the ages of 40 and 35 years, respectively; the cause of death could not be