Finally, however, Challenger, bent upon proving some point which Summerlee had contested, thrust his head over the rock and nearly brought destruction upon us all. In an instant the nearest male gave a shrill, whistling cry, and flapped its twenty-foot span of leathery wings as it soared up into the air. The females and young ones huddled together beside the water, while the whole circle of sentinels rose one after the other and sailed off into the sky. It was a wonderful sight to see at least a hundred creatures of such enormous size and hideous appearance all swooping like swallows with swift, shearing wing-strokes above us; but soon we realized that it was not one on which we could afford to linger. At first the great brutes flew round in a huge ring, as if to make sure what the exact extent of the danger might be. Then, the flight grew lower and the circle narrower, until they were whizzing round and round us, the dry, rustling flap of their huge slate-colored wings filling the air with a volume of sound that made me think of Hendon aerodrome upon a race day.

“Make for the wood and keep together,” cried Lord John, clubbing his rifle. “The brutes mean mischief.”