For the purpose of consolidating Federal holdings of land within Acadia National Park, the Secretary of the Interior is authorized to accept, on behalf of the United States, approximately fifty-eight acres of non-Federal land within the authorized park boundaries, such land to be conveyed to the United States without cost by Mr. John D. Rockefeller, Junior. Upon acceptance of title thereto by the United States, such property shall be subject to all laws and regulations applicable to the park. In exchange for the conveyance to the United States of the aforesaid property, the Secretary of the Interior is authorized to convey to Mr. John D. Rockefeller, Junior, or to such agency as he may designate, for purposes of the Jackson Memorial Laboratory, Bar Harbor, Maine, approximately five acres of federally owned land within the park adjacent to the laboratory properties.