But some birds, at least, do, indeed, receive instruction when on the wing. And in such cases, it will be noticed, their food can only be captured by dexterous movements in full flight. For a day or two, for example, young swallows simply practice flight, to exercise and strengthen their wings. They are fed by their parents when at rest. The next step comes when they are fed on the wing, taking their food as they hover on trembling pinions from their parent's beak. In a little while the food is dropped as the parent passes, and the youngsters are made to catch it as it falls. From thence, onwards, they have to do their own hunting. The clumsy ones must die. Eagles and hawks, in like manner, teach their young to capture swiftly moving prey by dropping food to them in mid-air. If one fails to catch it the parent swoops down and seizes the hard-won meal before it reaches the ground; then mounting aloft with it, drops it once more, till, at last the required dexterity is gained. [Illustration: Gulls.] CHAPTER IX. Flightless Birds. "And first, I praise the nobler traits Of birds preceding Noah, The giant clan, whose meat was Man, Dinornis, Apteryx, Moa."--_Courthope._ The steamer duck--The owl parrot--the flightless grebe of Titicaca--The dodo and solitaire--The ostrich tribe--The penguin's wings. The poet who penned the above lines thought more of rhymes than of reasons--as Poets so often do. What were their "nobler traits"? He omits to mention them. None of them were ever carnivorous: and the Apteryx could by no stretch of the imagination be called a "giant." The one outstanding feature which does distinguish these birds he fails entirely to appreciate--and this is their flightless condition. A flightless bird is an anomaly. Yet there are some who profess to believe that this state affords us an insight into the early stages of the Evolution of the wing. As a matter of fact it demonstrates the exact opposite--its degeneration. How is it that birds ever came to such a pass? A study of living flightless birds, and birds that are well on the way to this condition, will afford us a ready answer. Whenever we find birds living, so to speak, lives of languorous ease--where there are no enemies to be evaded, where there is an abundance of food to be picked up on the ground all the year round, and the climate is kindly, there flight is no longer practised. Year by year, generation after generation passes by, and no use whatever is made of the wings. In all such cases these once most vital organs dwindle away, and finally vanish. We can trace every step in this process of decay.