INTERPRETING the mood of the times, the editors X of this new series are presenting a number of books which they hope will help to recapture the inquiring and enthusiastic spirit of the old naturalists. Lately, as the editors are well aware, there have been many indications that it is once more being recognized that natural history is not inferior to science but is, indeed, an important part of science. This was shown, for example, in a biology syllabus for, sixth forms which was recently prepared by the Cambridge Joint Advisory Committee for Biology. The syllabus recommended that, in order to avoid the common complaint that whereas many botany students can discourse learnedly on a cross-section of the stem of Tilia europeea, they are unable to recognize the common lime when they see it, about a quarter of the time allotted to biology should be devoted to a study of plants and animals in their natural surroundings. (1) London's Natural History By R. S. R. Fitter. (The New Naturalist Series, No. 3.) Pp. xii + 282 + 72 plates. (London: Wm. Collins, Sons and Co., Ltd., 1945.) 16s. net. (2) Butterflies By Dr. E. B. Ford. (The New Naturalist Series, No. 1.) (pp. xiv + 368 + 72 plates. (London: Wm. Collins, Sons and Co., Ltd., 1945.) 16s. net.