2cS2 



INDEX. 



Pettigrew, Dr., on birds* wings, 210 

 piste, definition of, 152 



— of amble, 162 



— of slow gallop, 167 



— of Eclipse's gallop, 167 



— of trot, 157 



— of walking pace, 162 



Pline on stable equilibrium of birds, 

 216 



R. 



Reactions defined, 115 



— instruments to show, 116 



— of movements of wing of 



birds, 264 



— of walking (man), 127 



— of leap, ditto, 131 



— of gallop, ditto, 131 



— of trot of horse, 153 



— of gallop, ditto, 165, 171 

 Regnault's equivalent of heat, 15 

 Ressource of birds, 220 

 Reymond, du Bois, on muscular 



shocks, 50 

 Rhythm of paces, 133 

 Running (man), 125 



S. 



Selection, natural, 81 



•Shoe, experimental, 113 



Skeleton, action of aneurism on, 87 



— variability of, 85 



— change of course and at- 



tachment of 

 muscles, 89 



— — in, transmitted 



to descendants, 

 94 



— hollows worn by tendons 



in, 86 



Snail, movements of, 105 

 Stepcurves, 127 



: — of horse's trot, 153 



— — g^'tll^P? 165 



— — walk, 160 

 Stimulus of necessity, 83 

 Synthetic reproduction of move- 

 ments in man, 137 



— — in horse, 177 



T. . 



Temperature of animals, 23 

 Tetanus, muscular, 45 



— ■ from strychnine, 43 



— heat developed in, 49 



— Yolta and Weber on ner- 



vous, 45 

 Thermo-dynamics, 14 

 Torpedo, experiments on, 52 



— lost time in, 56 

 Tracings, see Table of Illustrations. 



— of walking pace (man), 



115 



— of running (man), 128 



— of gallop (man), 131 



■ — of hopping (man), 132 



— of leaping (man), 131 



— of movements of insect's 



wing, 190 seq. 



— of action of pectoral mus- 



cles of birds, 232 



— of flight of wild duck, buz- 



zard, &c., 266 



— of Wheatstone's rod with 



wing of wasp attached, 

 191 



— of humming-bird moth, 



191 



— compared with vibrations 



of chronograph, 121 

 Traction, effects of, on skeleton, 

 89 



Trajectory of pubis, 119 



— of bird's wing, 234-240 

 Transitions in paces of horse, 174 



U. 



Unit of heat, 13 

 — of work, 14 



V. 



Veratrine, muscle under, 35 , 

 Yilleneuve, Dr., on birds' wings, 223 

 Vincent and Goiffbn on horse, 151 

 Volta and Weber on nervous te- 

 tanus, 45 



