Knowledge of the history of the worship of the Church is very necessary for a proper understandingof its various rites, and at aperiod when that worship is. Undergoing reform in many particulars such knowledge is more than ever a necessary prerequisite. The present volume, specially written for the series by its general editor, forms an indispensable introduction to such a study of-liturgical history, for through the origin, evolution and history of the books of the Roman rite it offers a composite picturs of the development of worship in the West. After a short chapter on the Roman Missal (treated summarily in this volume since there are already two on the history of the Mass in this series) subsequent chapters deal with the Breviary, the Martyrology, the Pontifical and the Ritual. The last chapter of the book traces the history of the movement for liturgical reform as it has developed in this century, beginning with the work of St Pius X and culminating in the recent revised code of rubrics for Missal and Breviary. An appendix lists the minor books of ihe Roman rite, with short remarks on the more important of them.