18 ON NATURAL HISTORY MUSEUMS. A part only of the Gallery of the museum is at present given up to the natural history collections, but as these are rapidly increasing it is hoped that additional space may be secured in this section of the building, where the illumination by means of a direct top-light is well adapted for the display of objects requiring close inspection. The Botanical collection is located in the gallery. During the season fresh cut flowers are here exhibited week by week, as at the Forest Museum ; and the visitor is introduced to them by means of tablets adorned with charming little coloured sketches by Mr. Henry Cole. Here, too, are the Mineralogical and Petrological collections in course of arrangement by the skilful hands of Mr. Thomas W. Reader; and here, likewise, is the collection of Fossils—a collection containing many choice speci- mens, due chiefly to the generosity of Dr. Horace T. Brown, Mr. W. H. Dalton, and Mr. Carvalho. As an introduction to this section of the museum there is a most instructive series of specimens illustrating the phenomena of fossilization, and intended to answer the question which is asked by a bold tablet at the head of the case : "What is a fossil ?" In dealing with fossils a Curator is at once faced with the vexed question whether they should be arranged independently as a Palaeontological collection, or be associated with the zoo- logical and botanical specimens as one series—the extinct and the extant forms taking their place in juxtaposition. A fossil may in fact be viewed in two aspects : as a "medal of creation" it has an obverse and a reverse. The biologist looks at one side, the geologist at the other. To the biologist the fossil is a link in the chain of life, connected with other links on its two sides— a unit in a long organic concatenation related to certain antecedents and to certain successors. But the geologist, whilst fully appreciating this philosophical aspect, views the fossil as an index to a certain set of strata, as a representative of life at a particular period of the earth's history. After all, this question, whether a Curator should arrange his fossils on the biological or on the geological system, seems rather like the old question, "Whether the tailor should make coats or trousers." To which the very obvious retort was, "Why not make both ?" If the museum is extensive enough, there can surely be no valid reason why the two systems should not be followed. The Curator, realizing this, will do his best to satisfy at once the student of Life and the student of Time.