Biotech HOLDRS are depositary receipts issued by the Biotech HOLDRS Trust, and represent an undivided beneficial ownership in the common stock or American depositary shares of a group of specified companies that are involved in various segments of the biotechnology industry. The Bank of New York is the trustee. The 18 issuers of the underlying securities represented by a Biotech HOLDR, as of August 8, 2005, were Applera Corporation - Applied Biosystems Group, Affymetrix, Inc., Alkermes, Inc., Amgen Inc., Biogen IDEC Inc., Chiron Corporation, Applera Corporation - Celera Genomics Group, Genentech, Inc., Enzon Inc, Genzyme Corporation, Gilead Sciences, Inc., Human Genome Sciences, Inc., ICOS Corporation, MedImmune, Inc., Millennium Pharmaceuticals, Inc., QLT Inc., Sepracor Inc. and Shire Pharmaceuticals Group p.l.c.