Erratum.
In the letter by M. F. Balandrin and J. A. Klocke (13 Sept., p. 1036), it was incorrectly stated that nabilone (Cesamet) has been approved for marketing by the Food and Drug Administration. Nabilone has not yet been approved by the FDA. The synthetic cannabinoid recently approved is in fact dronabinol (Marinol), a synthetic form of delta-9-tetra-hydrocannabinol. In the same letter, the affiliation of the authors should have been Native Plants, Inc., not Nature Plants, Inc. In the original article by Balandrin et al. (7 June, p. 1154), references 23 and 65 were incorrect. They should have been as follows: 23. Y. Aharonowitz and G. Cohen, Sci. Am. 245, 140 (September 1981); 65. D. E. Eveleigh, Sci. Am. 245, 154 (September 1981).