Individual manuscripts are usually briefly designated in the ensuing notes and appendices by a single word indicating the place or collection where the MS is found and the number or shelf-mark of the individual MS. So many of the catalogues of MSS collections which I consulted were undated and without name of author that I have decided to attempt no catalogue of them. The brief designations that I give will be sufficient for anyone who is interested in MSS. In giving Latin titles, _Incipits_, and the like of MSS I employ quotation marks when I know from personal examination or otherwise that the wording is that of the MS itself, and omit the marks where the Latin seems rather to be that of the description in the manuscript catalogue or other source of information. In the following _List of Works Frequently Cited_ are included a few MSS catalogues whose authors I shall have occasion to refer to by name. LIST OF WORKS FREQUENTLY CITED BY AUTHOR AND DATE OF PUBLICATION OR BRIEF TITLE For more detailed bibliography on specific topics and for editions or manuscripts of the texts used see the bibliographies, references, and appendices to individual chapters. I also include here some works of general interest or of rather cursory character which I have not had occasion to mention elsewhere; and I usually add, for purposes of differentiation, other works in our field by an author than those works by him which are frequently cited. Of the many histories of the sciences, medicine, and magic that have appeared since the invention of printing I have included but a small selection. Almost without exception they have to be used with the greatest caution. Abano, Peter of, Conciliator differentiarum philosophorum et praecipue medicorum, 1472, 1476, 1521, 1526, etc. De venenis, 1472, 1476, 1484, 1490, 1515, 1521, etc. Abel, ed. Orphica, 1885. Abelard, Peter. Opera hactenus seorsim edita, ed. V. Cousin, Paris, 1849-1859, 2 vols. Ouvrages inédits, ed. V. Cousin, 1835. Abt, Die Apologie des Apuleius von Madaura und die antike Zauberei, Giessen, 1908. Achmetis Oneirocriticon, ed. Rigaltius, Paris, 1603. Adelard of Bath, Quaestiones naturales, 1480, 1485, etc. De eodem et diverso, ed. H. Willner, Münster, 1903. Ahrens, K. Das Buch der Naturgegenstände, 1892. Zur Geschichte des sogenannten Physiologus, 1885. Ailly, Pierre d’, Tractatus de ymagine mundi (and other works), 1480 (?). Albertus Magnus, Opera omnia, ed. A. Borgnet, Paris, 1890-1899, 38 vols.