Professor Griffith's treatise is a study of the sources of the Middle English metrical romance, "Sir Perceval of Galles," edited in 1844 for the Camden Society by J. O. Halliwell as one of "The Thornton Romances" preserved in the unique MS. of the Lincoln Cathedral library. As is well known to students of the Arthurian romances, this particular romance, though it strongly resembles Chrétien's "Perceval" in other respects, contains nothing about the Holy Grail, and so in the present study there is nothing that bears directly on the much-vexed question of the origin of that legend. Any discussion, however, of the sources of {Sir Perceval of Galles" is bound to be also, to a considerable extent, a discussion of the sources of Chrétien's poem and the other Grail romances, so that the book will be of interest to all students who have occupied themselves with this group of romances.