The reason for this state of things is that there is no food of any description to be had inland. Ages back, a different state of things existed: tropical forests abounded, and at one time, the seals ran about on shore like dogs. As conditions changed, these latter had to take to the sea for food, with the result that their four legs, in course of time, gave place to wide paddles or "flippers," as the penguins' wings have done, so that at length they became true inhabitants of the sea. Were the Sea-Leopards(2) (the Adélies' worst enemy) to take to the land again, there would be a speedy end to all the southern penguin rookeries. As these, however, are inhabited only during four and a half months of the year, the advantage to the seals in growing legs again would not be great enough to influence evolution in that direction. At the same time, I wonder very much that the sea-leopards, who can squirm along at a fair pace on land, have not crawled up the few yards of ice-foot intervening between the water and some of the rookeries, as, even if they could not catch the old birds, they would reap a rich harvest among the chicks when these are hatched. Fortunately however they never do this. (2) Sea-Leopard = _Stenorhinchus leptonyx_. [Illustration: Fig. 1. AN ANGRY ADÉLIE (Page 3)] When seen for the first time, the Adélie penguin gives you the impression of a very smart little man in an evening dress suit, so absolutely immaculate is he, with his shimmering white front and black back and shoulders. He stands about two feet five inches in height, walking very upright on his little legs. His carriage is confident as he approaches you over the snow, curiosity in his every movement. When within a yard or two of you, as you stand silently watching him, he halts, poking his head forward with little jerky movements, first to one side, then to the other, using his right and left eye alternately during his inspection. He seems to prefer using one eye at a time when viewing any near object, but when looking far ahead, or walking along, he looks straight ahead of him, using both eyes. He does this, too, when his anger is aroused, holding his head very high, and appearing to squint at you along his beak, as in Figure 1. After a careful inspection, he may suddenly lose all interest in you, and ruffling up his feathers sink into a doze. Stand still for a minute till he has settled himself to sleep, then make sound enough to wake him without startling him, and he opens his eyes, stretching himself, yawns, then finally walks off, caring no more about you. (Figs. 2 and 3.) The wings of Adélies, like those of the other penguins, have taken the form of paddles, and are covered with very fine scale-like feathers. Their legs being very short, they walk slowly, with a waddling gait, but can travel at a fair pace over snow or ice by falling forward on to their breasts, and propelling themselves with all four limbs.