THE WINGS. 69 



Some birds have to seek their food on the wing, consisting 

 of such very small insects that many hundreds must be swal 

 lowed for a meal, and in these we accordingly find a spread 

 and power of wing truly astonishing. We cannot take a 

 better example than our common Swift, whose well-known 

 scream and rapid flight must be familiar to every one. It has 

 to seek its livelihood solely in the air, on insects so small that 

 we can with difficulty perceive them, even if slowly passing 

 before our eyes. It could not, therefore, live a day, unless 

 gifted with extraordinary powers of flight ; it must not only 

 be able to move rapidly forward in a straight line, but also 

 be able to turn as quick as thought to the right or left, 

 upwards or downwards, to catch its minute prey. And such 

 is the case; the bird is so light that it weighs little more 

 than an ounce, and yet the spread of its wings, from tip 

 to tip, is not less than eighteen inches. But extraordinary 

 as these proportions are, in length of wing, compared with 

 weight, in this our British species, they are exceeded in a 

 species in the East Indies, called the Javanese Crested Swal- 

 low, whose uncommon length of wing indicates a speed far 

 beyond that of our Swift. Other birds, again, there are which 

 require additional powers, not in the air, but under water, their 

 food consisting entirely of the fish they are enabled to catch 

 by diving after them with greater speed than the fish can swim. 

 Here, it is evident, a long, widespreading wing, like the 

 Swift's, would be very inconvenient ; accordingly, in birds of 

 this tribe, we find the wings much smaller, and so formed that 

 they can be used as oars or fins, which in one division of the 

 Penguin tribe they very much resemble, the short feathery 

 covering upon them having much the appearance of scales. 

 Of the true Penguins we have none in this country, but we have, 

 however, many species, even in England, which live on fish, 

 having wings, if not so much like fins as those of the Penguins, 

 at least so very small, comparatively speaking, that we may 

 refer to them as illustrations of the subject before us, — we mean 

 the Divers or Grebes, one of the most beautiful of which, called 

 the Crested, or Eared, or Tippet Grebe, from a feathery orna- 



