BOSTON FERN, a variety (bostoniensis) of the sword fern (Nephrolepis exaltata) originated in cultivation. It was intro duced in 1895 by F. C. Becker and named in honor of the city of Boston, Mass., in the vicinity of which it was discovered. It is a strong, free-growing plant, with drooping, dark-green foliage, and is much less stiff in habit than the typical sword fern. It is one of the best ferns for decorative purposes, growing well in doors in pots or baskets, and is hardy out-of-doors in gardens and rockeries in the southern States. From this mutant, or from variants derived from it, have arisen numerous remarkable forms with very finely cut, crisped or otherwise peculiarly developed leaflets. Among these are the varieties elegantissima, robusta, magnifica and superbissima which are interesting also as examples of rapid evolutionary development.