INDEX. 



Action and reaction, 109 



Air, resistance of, changes plane of 



insect's wing, 197 

 Aliment, heating power of, 16 

 Animal motion, 27 

 Animals, high temperature of, 21 



— warm and coldblooded, 23 

 Apophyses, cause of, 89 

 Automatic regulator of temperature, 



25 



B. 



Beclard's experiments on heat and 

 work, 17 



Bernard on automatic regulator of 



temperature, 25 

 Bertrand on birds' muscles, 212 

 Biped diagonal, definition of, 154 

 Birds, conformation of, 216 



— curves in wing of, 210 



— electrical experiment on 



flight of, 231 



— flight of, 209 



— hovering of, 221 



— large pectoral muscles of, 211 



— M. de Lucy on, 222 



— muscular force of, 213 



— passades of, 220 



— rapidity of muscular action 



in, 214 



— ressource of, 220 



— sailing flight of, 221 



— stable equilibrium of, 216 

 Birds' wings, compared to screw, 211 



— — -fhiration of elevation 



and depression of, 229 



— — stroke of, forward and 



backward, 235 

 Blood, circulation of, 67 



Bones, change in thror^gh age, 90 

 Borelli on locomotion, 103 



— birds' muscles, 212 



— flight of birds, 273 



— horse, 161 



Buzzard, muscular force of wing of, 

 213 



C. 



Chronograph described, 122 

 Circulation of blood, variations in, 

 26 



— — furrows the 



bones, 87, 88 



Climbing, 106 

 Club-foot, 96 

 Creeping, 105 



Curnieu on Eclipse's gallop, 167 



D. 



Darwin's natural selection, 79 

 Darwinists, suggestions to, 84 

 Davy on torpedo, 52 

 Development theory, 78 

 Diptera, manner of flight of, 208 

 Dromedary, paces of, 173 ♦ 

 Duges on movements of horse, 139 

 Duhamel's chronographic tuning- 

 fork, 44 



Duval, representation of horse by 

 zoo trope, 177 



E. 



Electric fishes, 51 



