Sanatoria, memoranda, gymnasia are now replacing sanatorium, memorandums, and gymnasiums; automata, formulae, and lacunae are taking the place of automatons, formulas, and lacunas; indices and apices of indexes and apexes, miasmata of miasmas or miasms; and even forms like lexica, rhododendra, and chimeræ have been recently noted in the writings of authors of repute.