LIST OF PLATES. 



I. — Eagles soaring . . . . . . . . Frontispiece 



Facing 

 page 

 II. — Photographs of Pigeons and Gull, showing right 



and left wings giving different strokes . . . . 30 



III. — Photographs of — A : Pigeon using tail for mainten- 

 ance of equilibrium. B : Pigeon gliding. C : 

 Gulls gliding 36 



IV., V., and VI. — Photographs of Pigeons showing the 



phases of the wing-stroke in series . . 40, 42, 45 



VII. — Photographs of Gulls flying . . . . . . 46 



VIII. — A and B : Photographs of Pigeons starting to fly. 

 C : of Pigeon rising with body steeply inclined. 

 D : of Herring-Gulls starting . . . . . . 49 



IX. — Photographs showing different methods of steer- 

 ing — A and B : of Gulls. C and D : of Pigeons 60 



X. — A and B : Photographs of Pigeons alighting. C : 



of Pigeon checking speed . . . . . . 64 



XI. — A : Photograph of wing, showing elastic liga- 

 ment. B : of flight-feathers and tail-feather . . 85 



XII. — Drawing by I. C. Maclean (from Life and Evolu- 

 tion), showing minute structure of flight -feather 86 



XIII., XIV., XV.— Photographs of different types of 



wing 91, 92, 94 



XVI. — Photographs of Gulls with motionless wings fol- 

 lowing steamer . . . . . . . . . . 136 



IX 



