Art. 49 OG; statelessness and duty of naturalization under the Federal Act of 3 December 1850 and the Swiss-German settlement treaty of 31 May 1890; admissibility of a direct action against a canton. The Federal Council has primary competence to investigate whether the persons concerned possess cantonal or foreign nationality and to take the measures required for regularization. A judicial dispute before the Federal Court arises only if the canton refuses to accept the Federal Council's determination. The claimant is not entitled to bypass this administrative sequence and sue the canton directly.