Produced by Ron Swanson SEED DISPERSAL BY W. J. BEAL, M.S., PH.D. PROFESSOR OF BOTANY AND FORESTRY IN MICHIGAN AGRICULTURAL COLLEGE GINN & COMPANY BOSTON . NEW YORK . CHICAGO . LONDON COPYRIGHT, 1898 BY WILLIAM J. BEAL ALL RIGHTS RESERVED 36.11 The Athenaeum Press GINN & COMPANY . PROPRIETORS . BOSTON . U.S.A. PREFACE. This little book is prepared with the thought of helping young botanists and teachers. Unless the reader has followed in detail, by actual experience, some of the modes of plant dispersion, he can have little idea of the fascination it affords, or the rich rewards in store for patient investigation. A brief list of contributions to the subject is given; but, with very few exceptions, the statements here made, unless otherwise mentioned in the text, are the results of observations by the author. I am under obligations for suggestions by my colleague, Prof. W. B. Barrows; my assistant, Prof. C. F. Wheeler; and a former instructor of botany, L. H. Dewey, now of the United States Department of Agriculture. B. O. Longyear, instructor in botany, with very few exceptions, has made the drawings. W. J. BEAL. AGRICULTURAL COLLEGE, MICHIGAN. CONTENTS. CHAPTER I.--HOW ANIMALS GET ABOUT. PAGE 1. Most of the larger animals move about freely . . . . . . . . 1 2. Some animals catch rides in one way or another . . . . . . . 2 CHAPTER II.--PLANTS SPREAD BY MEANS OF ROOTS. 3. Fairy rings . . . . . . . . . . . . . . . . . . . . . . . . 4 4. How nature plants lilies . . . . . . . . . . . . . . . . . . 7 5. Roots hold plants erect like ropes to a mast . . . . . . . . 8 6. How oaks creep about and multiply . . . . . . . . . . . . . 8 CHAPTER III.--PLANTS MULTIPLY BY MEANS OF STEMS. 7. Two grasses in fierce contention . . . . . . . . . . . . . . 12 8. Runners establish new colonies . . . . . . . . . . . . . . . 13 9. Branches lean over and root in the soil . . . . . . . . . . 14 10. Living branches snap off and are carried by water or wind . 15 CHAPTER IV.--WATER TRANSPORTATION OF PLANTS. 11. Some green buds and leaves float on water . . . . . . . . . 18 12. Fleshy buds drop off and sprout in the mud . . . . . . . . . 20 13. Seeds and fruits as boats and rafts . . . . . . . . . . . . 22 14. Bits of cork around the seeds prevent them from sinking . . 24 15. An air-tight sack buoys up seeds . . . . . . . . . . . . . . 25 16. Fruit of basswood as a sailboat, and a few others as adapted to the water . . . . . . . . . . . . . . . . . . 27 CHAPTER V.--SEEDS TRANSPORTED BY WIND.