I wish further to make grateful acknowledgment of the assist ance given me by Mrs. Mabel E. Hodder, graduate student of Radcliffe College, Cambridge, in the revision and extension of the bibliographies of the Greek and Roman chapters; and of the aid I have received from my former pupil, Miss Lucy M. Blanchard, who has kindly given me the benefit of long class-room use of the earlier work by making various suggestions which I have found very helpful.