In the matter of organization the _Bibliotheca bibliographica_ has long been regarded as a model. Nevertheless one cannot defend Petzholdt's inclusion[149] of a detailed list of schemes for classifying books. He had collected a great deal of information about such schemes because they interested him as a librarian, but the subject is not pertinent to a bibliography of bibliographies. Petzholdt's relegation of the alphabetical index of authors to a clerk or, if he did have a clerk, to as inaccurate a clerk as he chose, was unfortunate. His decision to provide no alphabetical index of subjects makes the _Bibliotheca bibliographica_ hard to use. His exclusion of articles in journals denies the purpose and spirit of bibliography. If bibliographical collections are to guide seekers after knowledge to information, then a bibliographer cannot justify the deliberate neglect of materials which do not happen to be in a particular physical condition. The best bibliography of the Tuamotus may be, let us say, in a journal article. The bibliographer who is aware of it and omits it merely because it is a journal article is guilty of a serious fault. We can pardon him for not finding it, but we cannot pardon him for rejecting it. We must not confuse the situation by making such an excuse as "avoiding the burden of inconsequential references." Petzholdt deliberately omitted journal articles and therefore does not serve the man who comes to his book as fully as he might have served him. Petzholdt's inclusion of books dealing with the invention, history, and practice of printing stretches the definition of his purpose, but custom is on his side and we shall not protest unduly. Lists of books issued by a famous publisher are of course within the scope of the _Bibliotheca bibliographica_.