ANIMAL LOCOMOTION OR WALKING, SWIMMING, AND FLYING, WITH A DISSERTATION ON AERONAUTICS. 591.5 49027 BY J. BELL 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 Extraordinary Member and late President of the Royal Medical Society of Edinburgh; Croonian Lecturer 1872; Author of numerous Memoirs on Physiological Subjects in the 11 LUSTRATED BY 130 ENGRAVINGS ON WOOD. NEW YORK: D. APPLETON AND COMPANY, 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 happy to state, have in no way deteriorated in his hands. CONTENTS. Motion associated with the life and well-being of animals, 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, The extremities of animals in walking act as pendulums, and In swimming, the body of the fish is thrown into figure-of-8 The tail of the fish made to vibrate pendulum fashion, The tail of the fish, the wing of the bird, and the extremity of 12 |