Establishment of stakes within mission boundaries-- ... thirty-seven new stakes of the Church had been organized. Many of these were now in the mission fields of the Church ... "To Presidents of Missions and Stakes Whose Territorial Boundaries May Overlap or Are of Such Character That the Work of Missions May be Carried Forward Within the General Boundary Line of Stakes." The establishment of stakes in mission territory "shall not be deemed so rigid as to preclude mission work within such boundaries. It being understood, however, that the jurisdiction of stake and ward authorities over units which are set up and maintained in the stake is exclusive."
[1947-July 15-Original circular letter, L.D.S., in Clark, James R., Messages of the First Presidency (6 volumes)]