FOSSIL PLANTS CAMBRIDGE UNIVERSITY PRESS ~London~: FETTER LANE, E.C. C. F. CLAY, MANAGER [Illustration] ~Edinburgh~: 100, PRINCES STREET ~London~: H. K. LEWIS, 136, GOWER STREET, W.C. ~Berlin~: A. ASHER AND CO. ~Leipzig~: F. A. BROCKHAUS ~New York~: G. P. PUTNAM’S SONS ~Bombay and Calcutta~: MACMILLAN AND CO., LTD. _All rights reserved_ [Illustration: Part of a transverse section of a Permian Osmundaceous Fern stem, _Thamnopteris Schlechtendalii_ (Eichwald). _a_, outer xylem; _b_, inner xylem. For description, see page 329. (After Kidston and Gwynne-Vaughan. Very slightly reduced.)] FOSSIL PLANTS A TEXT-BOOK FOR STUDENTS OF BOTANY AND GEOLOGY BY A. C. SEWARD, M.A., F.RS. PROFESSOR OF BOTANY IN THE UNIVERSITY; FELLOW OF ST JOHN’S COLLEGE AND HONORARY FELLOW OF EMMANUEL COLLEGE, CAMBRIDGE WITH 265 ILLUSTRATIONS VOL. II CAMBRIDGE: AT THE UNIVERSITY PRESS 1910 ~Cambridge~: PRINTED BY JOHN CLAY, M.A. AT THE UNIVERSITY PRESS. PREFACE I regret that pressure of other work has prevented the completion of this Volume within a reasonable time since the publication of Volume I. Had Volume II been written ten years ago, the discoveries made in the course of the last decade would have given an out-of-date character to much of the subject-matter. It is more especially in regard to the Ferns and the extinct members of the Gymnosperms that our outlook has been materially altered by recent contributions to Palaeobotany. It is, however, some satisfaction to be able to add that recent progress has been relatively slight in that part of the subject dealt with in the first volume.