Professor Michael Foster somewhere remarked that “hypothesis is the salt of science.” The main difficulty with which observers in the field have to contend is that, as a rule, they can see only what they look for. When an investigator has left his field and is working up his results at home, he only too frequently finds that he has omitted to look for certain customs or beliefs, whose occurrence in other places he had either over-looked or forgotten. This is the justification for the questionnaires. It is one of the most important functions of stay-at-home synthetic students laboriously to cull data from the vast literature of anthropology, travel, and ancient and modern history, and to weld them into coherent hypotheses. The student at home in this way suggests fresh inquiries to the field ethnologist, and a richer harvest is the result. The most valuable generalisations are made, however, when the observer is at the same time a generaliser; but “doubtless,” as Maharbal said to Hannibal after the battle of Cannae, “the gods have not bestowed everything on the same man. You, Hannibal, know how to conquer; but you do not know how to use your victory.” The vastness of the anthropological sciences and the nebulous character of their demarcation from other sciences render their definition or classification a peculiarly difficult matter. Even at the present day students are not agreed upon the exact terminology and limitations of the various branches of their subject; but, after all, these are little more than academic discussions, since investigations go on irrespective of boundary lines. Those who are really worried about this “terminological inexactitude” are the cataloguers and librarians, who frequently are at a loss where to place items in their catalogues or books on their shelves. It was mainly from this point of view that Dieserud was constrained to write his _Science of Anthropology: Its Scope and Content_.[1] This useful little book deals very fully in historical order with the questions referred to above, and it may be recommended to those who are interested in these somewhat profitless discussions. Footnote 1: This is the title on the back of the book. Its designation on the title-page is given correctly in the Bibliography. For the convenience of those who require landmarks we here give the scheme that is roughly followed in this book, which is based upon the classification recently proposed by the Board of Studies in Anthropology of the University of London as a guide for the study and teaching of Anthropology:— _A._—PHYSICAL ANTHROPOLOGY (Anthropography, Anthropology of some writers) (_a_) _Zoological_ (somatology, including craniology, etc.).—Man’s place in Nature as evidenced by the study of comparative anatomy and physiology, more especially of the Anthropoidea.