In all cities that now have or hereafter may have four hundred thousand inhabitants or over, it shall be unlawful to sell, trade or otherwise convey or to offer to sell, trade or otherwise convey any lot or parcel of land as a part of or in conformity with any plan, plat or replat of any subdivision or portion of the city unless said plan, plat or replat shall have first been recorded in the office of the recorder of deeds of said city.