j56 The Library. Lyell (C.) The Geological Evidences of the Antiquity of Man (1863). Murchison's Siluria. Spencer (Herbert) Principles of Biology. Sowerby's English Botany or coloured figures of British Plants, ii vols (1864.) Burmeister's Manual of Entomology, translated by Shuckard (1836). Miller (Hugh) Old Red Sandstone. And, again, among standard works should be included numerous atlases of plates, large and small, folio et infra. The descriptions may be at fault, but the lithographed depictions rarely. The careful and painstaking execution of the latter compares favourably with modern work of the same kind. Lastly, the transactions of learned societies and sets of certain journals should be kept intact, not because everything they contain is of value, but because they form, as it were, a con- tinuous history of the gradual advance of knowledge. Among these may be mentioned the following : Philosophical Transactions of the Royal Society; Journal of the Linnean Society; Transactions and Proceedings of the Zoological Society, and Annals and Magazine of Natural History. But all said and done, the fact remains that if a book has to be written which shall cover the whole field of one par- ticular branch of knowledge (and that, surely, is the correct definition of a text-book), the value of the first edition can never be permanent, because in some quarter or another fresh truth brought to light often subverts a previous theory. The rapid strides made in these various branches are daily being chronicled, not only in scientific journals, but in lay newspapers as well, and the discoveries of investigators are duly announced week after week. The latest facts are constantly being made known in physiology, biology whether relating to plant or animal life, chemistry, pathology, bacteriology, astronomy, electricity and engineering. So here we are left face to face with the problem as to what we are to do with those text-books, worthless in the eyes of science, that crowd our book shelves. In dealing with a practical question it is hard to eliminate the play of imagination, and not to wish that there was some race of men in distant climes, some band of colonists of our own nation, who, ignorant and untaught, were willing to begin simply on the knowledge our fathers had, and to go through the mis- takes before they got to the truth. That indeed would be an