The recent case of Factor v. Laubenheimer raised several interesting questions with regard to the date of effectiveness of the extradition treaty between the United States and Great Britain, signed at London, December 22,1931, and the effect, if any, of the President’s proclamation of the treaty upon its status as law of the land of the United States. Article 18 of the treaty provided that it was to “come into force ten days after its publication, in conformity with the forms prescribed by the laws of the high contracting parties.” Ratifications were exchanged at London, August 4,1932; the President issued a proclamation in the usual form containing the treaty, as of the date August 9,1932; but the British Government withheld the issuance of an Order-in-Council containing the treaty, apparently to avoid affecting the result in the Factor Case. Counsel for the petitioner argued that the treaty was in force, but the Supreme Court, without going into the merits of the contention, followed the State Department, which appeared not to have recognized the treaty as in force in either country. The court, after examining the terms of the 1931 agreement found that even if it had come into effect as contended it would not have abated the pending proceedings. In several previous cases incidentally involving Presidential proclamations of treaties, the court has also been able to dispose of the principal issues raised without pronouncing upon the status and effect of such proclamations. On some future occasion, perhaps, the court may find it necessary to rule squarely upon the relation of the President’s proclamation of an international agreement to its status in domestic law. The present discussion is devoted to an examination of that relation, which includes the date of effectiveness of a treaty; the history of the use of the proclamation; and the effect of the proclamation upon the status of the treaty as law of the land.