Male Fern, Dryopteris filix-mas. Official in all pharmacopeias. The Spanish standard calls it Polypodium filix-mas. A teniafuge efficacious against the Bothriocephalus and to a lesser degree against the Toenia or true tapeworm, in which pelletierin (q. v.) is to be preferred.

Aspidium is quite toxic, when absorbed. Never follow its administration with oil in any form. The average dose of Oleoresina Aspidii (U. S. P.) is 30 grains. It may be given in emulsion or in capsules. Filmaron is obtained from the ethereal extract of aspidium and is claimed to be devoid of the injurious by-effects of the oleoresin and the toxic substances soluble in oil. Filmaron oil is a 10 per cent solution of filmaron in castor oil. Dose: 2 1/2 fluidrachms.