universities, and Jesuit colleges, (12) writers of catalogues and eulogies of individual academies and their faculties, (13) writers on the inventors of things, arts, and sciences. In order to fit his material into this pattern Labbé changes his procedure and writes in an individual entry in No. 10 above: "Manuscriptorum catalogus varias exhibent Antonius Sanderus, Aubertus Miraeus,..." In other words, the subject heading takes the place of a heading in terms of the author. The fifth index lists bibliographers of men who have borne the same name. Anton Sander's book on Antonies is an example. Such works were very popular in Labbé's day and deserved this special attention. The sixth index is a list of bibliographies, which are often autobibliographies, of individual writers and of indexes to their works. The seventh index includes publishers' and booksellers' catalogues. In the somewhat confused eighth index, which again illustrates the difficulty already discussed, Labbé intended to list bibliographies having a proper name in their titles. Here are found books on the Ambrosian and Amsterdam libraries, Labbé's own anti-Jansenist bibliography, and an anonymous catalogue of anti-Jesuitica. He preferred to put the last two bibliographies here and not in the third index, which contained religious bibliographies. He had already set up a category for writers about the Virgin Mary in the fourth index, but he named others in the eighth. I cannot see why he placed writers of dictionaries in the eighth and not in the fourth index, and certainly he should have put writers on chemistry and politics in the first and not the eighth index. These irregularities are difficult to explain. In a search for a subject bibliography a modern reader must turn to the first, fourth, and eighth indexes. He will find a national or local biobibliography in Index II, a biobibliography of a religious order in Index III, a list of works on homonyms in Index V, a bibliography of an individual author in Index VI, and a catalogue issued by a publisher or bookseller in Index VII. The classification is complicated but not altogether unusable. In the eleven years that passed between the first publication of the _Bibliotheca bibliothecarum_ and its final appearance in 1664, Labbé might have worked out the details more carefully than he did. We can of course pardon some faults because modern bibliographers are more demanding than those of 1664. We may, however, say fine words about these demands and be forced to eat our words when we look later in this essay at the modern bibliographies of Léon Vallée, Henri Stein and the very recent work of Hanns Bohatta and Franz Hodes. While we are mindful of the old saying about those who live in glass houses, we can nevertheless point out inconsistencies, irregularities in procedure, awkward arrangements of materials, and outright errors. The faults to be found in Labbé's book are relatively slight and do not seriously impair its value.