CHAPTER VII. 



The Machinery of Flight. 



The Breastbone and the Connected Bones — Muscles and 

 Quality of Muscle — The Scaffolding of the Wing — Pneu- 

 matic Bones — Stiffness of Wing — Expanse of Bone — 

 The Spreading of the Wing — Structure of a Flight- 

 Feather — Moulting — Legs . . . . . . 67 



CHAPTER VIII. 



Varieties of Wing and of Flight. 



Curve — Narrow and Broad Wings — Styles of Flight — Flight 



in Flocks— The Whir of Wings 91 



CHAPTER IX. 



Pace and Last. 



Experiments and Observations — Wind — Velocity of Migra- 

 tory Flights — Endurance . . . . . . . . 103 



CHAPTER X. 



Wind and Flight. 



Rising — Flight with the Wind — Undulating Flight 

 without Movement of the Wings — Advance in a Direct 

 Line without Movement of Wing — Advance Sideways 

 in a Direct Line — Soaring — Soaring in a Horizontal 

 Wind Impossible.. .. .. .. .. .. 120 



CHAPTER XL 



Some Accessories. 



Digestion — Circulation, Breathing, Temperature — Repair 



of the Machine — Call-notes and Song . . . . . . 154 



