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 cold blooded, 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 

 B rds, 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 



duration of elevation 



and depression of, 229 



stroke of, forward and 



backward, 235 

 Blood, circulation of, 67 



Bones, change in through 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 

 Cnruieu 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 

 Duhamei's chronogr;iphic tuning- 

 fork, 44 



Duval, representation of horse by 

 zoo trope, 177 



E. 



Electric fishes, 51 



