Plaintiff, the transferee after maturity of certain promissory notes made by defendant in Florida, sued in his own name on the notes in the Federal District Court for Pennsylvania. Under the Pennsylvania practice, an assignee after maturity could not sue in his own name unless the notes were negotiable. The District Court concluded that the notes, which contained a provision for interest on overdue interest payments, were non-negotiable and sustained a demurrer. This was affirmed by the Circuit Court of Appeals for the Third Circuit on the ground that although the Florida Negotiable Instruments Law was the law of the case and was alleged to have been interpreted by the courts of that State as making this type of note negotiable, the federal court was free to adopt its own view of state statutes declaratory of the general commercial law. Held, that the case should be reversed because the federal courts are bound to follow state decisions interpreting statutes declaratory of commercial law as well as other statutes. Burns Mortgage Co., Inc. v. Fried, (U.S. 1934) 54 Sup. Ct. 813.