The BODY presents the following regions: first there is the _breast_ (22), which extends over the space which covers the breast-bone. To this succeeds the _belly_ (29), which is terminated by the _vent_ or _crissum_ (30). Immediately behind the vent are the _under-tail covers_ (32), which are frequently of a different colour from the surrounding feathers. On the upper aspect of the body we have the _interscapular region_, sometimes called the _back_ (24), to which succeeds the _lower back_ (26), which terminates at the _rump_, or that part where the _upper-tail covers_ (42) are inserted. Last of all comes the TAIL, composed of long stiff feathers, called the _tail-feathers_ (31), concerning which it is only necessary to observe that the two middle tail-feathers are the _intermedial_, while those on the sides are the _lateral_ tail-feathers. The WING of a bird will be found to present a structure worthy of our highest admiration. The object aimed at in the arrangement of its different parts is evidently to obtain a very large and firm expanse of surface, by employing the smallest possible quantity of material. For the purposes of flight it is obviously necessary that the superficial extent of the wings shall be sufficiently ample, not only to sustain the weight of their possessor in the thin and yielding element in which it flies, but, by the vigour of their stroke and the violence of their impulse, to propel the bird with a rapidity proportioned to the occasion, and, moreover, by the lightness of their touch and the accuracy of their movements, to steer and steady its course through all the varied evolutions whereby it is enabled to capture prey, or sportively display the wonderful activity conferred upon the feathered tribes.