Derivation.—The rhizome of Aspidium Filix-mas. Collected late in the autumn, divested of its roots, leaves and dead portions, and carefully dried. Male fern should not be kept more than a year.

Habitat.—The male fern grows wild throughout most temperate regions, on the sides of roads and in open woods, especially where the soil is light.

Properties.—Its root stock is perennial, about a foot long and two inches thick; is scaly, tufted, greenish-brown, and firmly fixed in the ground by numerous black root fibers. The dried root has a disagreeable odor, and a sweet, astringent, nauseous taste. Powdered male fern should be freshly prepared and have a bright green color.

Dose.—The powdered male fern is given to horses and cattle in doses of 4 to 6 ozs.; sheep and pigs, 1 to 4 ozs.; dogs and cats, ¹/₂ to 2 ozs. The powder is bulky, and less certain than the oleoresin of aspidium.

PREPARATIONS

OLEORESINA ASPIDII—OLEORESIN ASPIDIUM—OLEORESIN MALE FERN

Made by percolation with ether, distillation and evaporation of the ether.

Dose.—Horses and cattle, 3 to 6 drs.; sheep and pigs, 1 to 2 drs.; dogs and cats, 15 ms. to 1 dr.

Action and Uses.—Male fern is irritant, vermicide laxative, large doses of the drug cause hemorrhagic gastro-enteritis, tremors, weakness, stupor, coma, acute nephritis and cystitis. Oleoresin of male fern is one of the most effectual remedies for tapeworm, particularly those inhabiting dogs.