To those who have used this work of reference, the new issue requires no commendation. For those who have not yet handled it, emphasis may be laid on the words from the title-page: "Compiled from Official Sources." The information provided as to the titles, addresses, officers, and activities of the scientific and learned societies and Government institutions in Great Britain and Ireland has been obtained from officials of the societies concerned, so the volume serves as a directory. In addition, the lists of authors and titles of papers presented before each society during 1925 gives some indication of the amount and direction of progress made in science and the arts. Take, for example, the Royal Society: the total number of papers, 226, shows great activity in the scientific world, while the fact that nearly three-quarters of them were published in Series A of the Transactions or Proceedings testifies to the fertile field of the mathematical and physical sciences. The various societies are grouped according to the subjects of their interests, beginning with those dealing with science generally. As regards classification, there will obviously be differences E of opinion; we think, however, that the Rontgen Society would be better in the Physics Section I than under Chemistry and Photography, while the Spelaeological Society (University of Bristol) is certainly archaeological rather than biological. The index, however, soon smooths out little difficulties of this kind. The new address of the British Cast Iron Research Association, at 24 St. Paul's Square, Birmingham, was probably announced too late for insertion. We are still of the opinion that all the research associations in Great Britain now in existence should be included and indexed under ' Research.' Some of the more recently formed scientific bodies have not yet appeared in the volume, but meanwhile we must be grateful for the valuable collection of data with which the publishers of this-annual continue to supply us.