The subject of Palaeobotany does not readily lend itself to adequate treatment in a work intended for both geological and botanical students. The Botanist and Geologist are not always acquainted with each other’s subject in a sufficient degree to appreciate the significance of Palaeobotany in its several points of contact with Geology and recent Botany. I have endeavoured to bear in mind the possibility that the following pages may be read by both non-geological and non-botanical students. It needs but a slight acquaintance with Geology for a Botanist to estimate the value of the most important applications of Palaeobotany; on the other hand, the bearing of fossil plants on the problems of phylogeny and descent cannot be adequately understood without a fairly intimate knowledge of recent Botany. The student of elementary geology is not as a rule required to concern himself with vegetable palaeontology, beyond a general acquaintance with such facts as are to be found in geological text-books. The advanced student will necessarily find in these pages much with which he is already familiar; but this is to some extent unavoidable in a book which is written with the dual object of appealing to Botanists and Geologists. While considering those who may wish to extend their botanical or geological knowledge by an acquaintance with Palaeobotany, my aim has been to keep in view the requirements of the student who may be induced to approach the subject from the standpoint of an original investigator. As a possible assistance to those undertaking research in this promising field of work, I have given more references than may seem appropriate to an introductory treatise, and there are certain questions dealt with in greater detail than an elementary treatment of the subject requires. In several instances references are given in the text or in footnotes to specimens of Coal-Measure plants in the Williamson cabinet of microscopic sections. Now that this invaluable collection of slides has been acquired by the Trustees of the British Museum, the student of Palaeobotany has the opportunity of investigating for himself the histology of Palaeozoic plants.