STANFORD LIBRARY J. BFLL PETTIGREW, M.D. F.R.S. F.R.S.E. F.R.C.P.E. FATHOLOGIST TO THE ROYAL INFIRMARY OF EDINBURGH; CURATOR OF THE MUSEUM OF THE ROYAL COLLEGE of suRGEONS OF EDINBURGH; Extraordinary Member and late President of the Royal Medical Society of Edinburgh; Croonian Lecturer to the Royal Society of London for 1860; Lecturer to the Royal Institution of Great Britain and Bussell Institution, 1867; Lecturer to the Royal College of Surgeons of Edinburgh, 1872; Author of numerous Memoirs on Physiological Subjects in the ALAMEDA COUNTY JPBABY ILUSTRATED ER 10 ENGRAVINGS ON WOOD. 1452 D. APPLETON AND COMPANY, 1, 3, AND 5 BOND STREET. 1893. PREFACE. In the present volume I have endeavoured to explain, in simple language, some difficult problems in "Animal Mechanics." In order to avoid elaborate descriptions, I have introduced a large number of original Drawings and Diagrams, copied for the most part from my Papers and Memoirs "On Flight," and other forms of “ Animal Progression." I have drawn from the same sources many of the facts to be found in the present work. My best thanks are due to Mr. W. Ballingall, of Edinburgh, for the highly artistic and effective manner in which he has engraved the several subjects. The figures, I am deteriorated in his happy to state, have in no way hands. ROYAL COLLEGE of Surgeons of EDINBURGH, CONTENTS. Motion not confined to the animal kingdom; all matter in Flight a more unstable movement than that of walking and swimming; the travelling surfaces and movements of ani- mals adapted to the earth, the water, and the air, The earth, the water, and the air furnish the fulcra for the levers formed by the travelling surfaces of animals, PAGE 23456 |