Now in his seventies, one of America's distinguished doctors records his life. Formal, old-school, largely documentary, this biography will appeal to a market of his fellows rather than to the general reader. (Though the Hugh Young and Finney biographies reached a much wider market than advance reading would have indicated.) Dr. Barker was born in modest circumstances in Canada, of Quaker parentage and rearing; he received a scholarship to medical school in Toronto after working as a pharmacist's apprentice. He made up his mind to work under Osler, after graduation, and received an appointment to Johns Hopkins, where he spent two decades, interrupted by medical commissions to the Philippines, to India, and five years at the University of Chicago where he held the Chair of Anatomy. From there he returned to Johns Hopkins, to succeed Osler as Head of the Department of Medicine. Eventually, he resigned, to continue medicine in private practice. There is a preponderance of data on research, on medical reforms, on addresses and lectures and honors -- for the record; and too little of his personal life, his pastimes, the man himself. Sometimes heavy going.