Page:Popular Science Monthly Volume 9.djvu/158
THE POPULAR SCIENCE MONTHLY.
inches farther they appear to be double. A model of them at this part of the tube can be obtained by locking the fingers of both hands one into the other. Just as the trachea leaves the bony box it is considerably enlarged.
Of course, the use of this curious structure is to produce those wonderful sounds which are peculiar to the crane. In fact, it is a portion of a cornet-à-piston or trombone, and is, no doubt, worked by some very delicate muscles. I have never had the pleasure of seeing cranes fly in the air, but I am told that the noise they make is very wonderful. We read: "Cranes range, according to the season, from the north of Europe to the south of Asia, and north of Africa, and in the latter country they are said to extend their migrations as far as the Cape of Good Hope. On these excursions they fly high in the air, though they experience some difficulty in getting on the wing from the ground. Before taking their spring they run some paces, raise themselves a little at first, and then unfold a powerful and rapid wing. In the air they form very nearly an isosceles triangle, possibly for the purpose of cutting the element with greater facility. When attacked