330 STERNA OF ACC1PITRES. 



may be obtained by looking back at the sketch of the 

 most perfect of the whole, the jer-falcon, at page 98. 

 The short-winged hawks, eagles, buzzards, kites, and 

 harriers follow ; and after them the fishing eagles, 

 the vultures, and the skuas, which last, though they 

 do not kill game, yet rush upon the gulls and other 

 birds, which they plunder, with strong and rapid wing. 

 They have, no doubt, their sternal apparatus some- 

 what modified so as to accord with tlicir webbed feet 

 when they do take to the water, but still they are 

 chiefly and characteristically air-birds. 



The secretary falcon, which combines with some of 

 the characters of the diurnal birds of prey some of 

 those of the grallidae, which frequent not the waters 

 or their margins, has the keel of the sternum less 

 perfect, the posterior edge terminating in a point, and 

 the general outline curved something in the same 

 manner as that of the wingless birds. The clavicle 

 has also an enlarged process at the junction of the 

 two branches, which rests upon the sternum ; and the 

 ooracoid bones are proportionally much longer than 

 in the typical birds of prey. There is, in short, 

 enough in the structure of this bird (and the habit 

 corresponds) to show that it ought not to be classed 

 with the accipitres ; but not enough to bring it pro- 

 perly into any other order or family. 



In the nocturnal birds of prey there are also con- 

 siderable differences in the formation of the sternal 

 apparatus. The snowy and eagle owls, which are 

 more bold and daring than the rest, have the furcal 

 bone more powerfully formed, and the keel of the 

 sternum better developed than in the common owls, 

 which are birds of weak flight, feeding on reptiles 

 and small mammalia, and chiefly in the twilight. But 

 the whole of this division have the skeleton so much 



