This annual report of the Assembly of Life Sciences (ALS) covers the fiscal year beginning July 1, 1977, and ending June 30, 1978. This report has four major sections on the Executive Office, the Division of Biological Sciences, the Division of Medical Sciences, and the Board on Toxicology and Environmental Health Hazards. The activities in each section are listed alphabetically. Organization charts at the beginning of each section show the structure within the ALS and the Assembly's relation to the National Academy of Sciences (NAS). A list of all reports completed by ALS committees during the year and a list of the Corresponding Societies of the Assembly are found at the end of this report. (Author/BB)