vi 



CONTENTS. 



PAGB 



The body and wing reciprocate in flight ; the body rising when 



the wing is falling, and vice versa, , . .12 



Flight the least fatiguing kind of motion. Aerial creatures not 



stronger than terrestrial ones, . . . .13 



Fins, flippers, and wings form mobile helics or screws, , 14 



Artificial fins, flippers, and wings adapted for navigating the 



water and air, . . . . . . 14 



History of the figure-of-8 theory of walking, swimming, and 



flying, ....... 15 



Priority of discovery on the part of the Author. Admission to 



that eff'ect on the part of Professor Marey, . . 16 



Fundamental axioms. Of uniform motion. Motion uniformly 



varied, . . . . . . .17 



The legs move by the force of gravity. Resistance of fluids. 

 Mechanical eff"ects of fluids on animals immersed in them. 

 Centre of gravity, ..... . 1 8 



The three orders of lever, . , . , ,19 



Passive organs of locomotion. Bones, . • . ,21 



Joints, ........ 23 



Ligaments. Efl'ects of atmospheric pressure on limbs. Active 

 organs of locomotion. Muscles ; their properties, arrange- 

 ment, modes of action, etc., . . . .24 



Muscular cycles. Centripetal and centrifugal movements of 

 muscles ; muscular waves. Muscles arranged in longitu- 

 dinal, transverse, and oblique spiral lines, . . 2^-27 

 The bones of the extremities twisted and spiral, . . 28 

 Muscles take precedence of bones in animal movements, . 29 

 Oblique spiral muscles necessary for spiral bones and joints, . 31 

 The spiral movements of the spine transferred to the extremi- 

 ties, . . . . . . .S3 



The travelling surfaces of animals variously modified and 



adapted to the media on or in which they move, • , 34-36 



PROGPvESSION ON THE LAND. 



Walking of the Quadruped, Biped, etc., . . . 37 



Locomotion of the Horse, . . . . .39 



Locomotion of the Ostrich, . . . . ,45 



Locomotion of Man, . . . . . .51 



