_Heortology_, a History of Christian Festivals from their Origin to the Present Day, by Dr. Kellner, Professor of Catholic Theology in Bonn, is a translation of a text-book written for German students preparing to pass Government examinations. It is a fine book, and if a student of liturgy knew its contents well he would have no poor knowledge of this and, incidentally, of other questions of liturgy. Gueranger, Duchesne and Kellner constitute the beginnings of a student's liturgical library (London, Keegan, Paul. 1908. Price 10s. 6d.). An excellent little volume by Father McKee, dealing with the same subject, is published by Catholic Truth Society, London, 2s, 6d. It is introductory and elementary. 10. Thousands of works on the Psalms have been published. But any priest or student who studies Steenkiste's work on the Psalms learns nearly all that is needed to recite his psalms digne, attente ac devote. His work is a mine of useful, pious, and, in the main, accurate comment on the inspired text. Breviary students studying this commentary need little else to help them to admire, to understand and to use their psalmody in a prayerful manner. Steenkiste, _Liber Psalmorum_ (3 vols, Bruges. 1886. Price 15s.). _The New Psalter of the Roman Breviary_, by Fillon, S.S. (London, Herder. 1915. Price 6s.). Father Fillon was consultor to the Biblical Commission. His notes are short and useful to those who, having studied the psalms, can recall their meaning by a few brief hints. Its comments are too brief, but it gives the Latin text, English translation, notes on psalms and newly added canticles, and is arranged in the order in which they stand in the Pian psaltery. _Sing Ye to the Lord_, by Rev. R. Eaton (London, Catholic Truth Society. 2 vols. 4s. each). In these books the leading idea or ideas of the Psalms are taken up, and beautiful explanations and spiritual readings given. The books are delightful reading, and give Breviary readers, old and young, fresh thoughts on psalms which through familiarity and constant repetition may have lost some of their pious meaning and prayerfulness. Books of Scripture commentary by non-Catholic writers should be read with caution, and often ecclesiastical permission for their perusal must be sought. Neale and Littledale's _Commentary on the Psalms_ (6 vols. London. 1867) is a compilation by two Anglican scholars, from the commentators of the Middle Ages. The wonderful piety of these men of old, saints and scholars, their beautiful comments, their glowing fervour, and above all their knowledge and love of the Bible text, surprise us all. Sometimes, of course, these mediaevalists run into far-fetched, outlandish comments, but the compilers give always the comments of the Masters, St. Thomas, St. Bede, etc.