All lands purchased from funds heretofore allocated and made available by Executive order, or otherwise, for the acquisition of lands for conservation or forestation purposes within the maximum boundaries of the Mammoth Cave National Park as authorized by , are made a part of the said park as fully as if originally acquired for that purpose and the proviso at the end of shall not be construed so as to prohibit the acquisition of lands in said area under funds made available as aforesaid.section 404 of this titlesection 404 of this title