90 ORGANS OF SUPPORT, 



their modifications are therefore intimately connected with 

 the general forms of the skeleton, and the living habits of 

 the species. The tipper bill is long and hooked in fishing 

 birds, shorter in vultures, and still shorter in eagles and 

 hawks. The jaws are long, straight, tapering, and pointed 

 in herons and storks, shorter and slender in wood-peckers, 

 and still more slender and pointed in insectivorous singing 

 birds. They are long and curved in the ibises, and curlews, 

 and humming birds, short, conical and strong in the gallin- 

 aceous and granivorous birds, and still shorter and stronger 

 in the parrots and cockatoos, to break the hard nuts on which 

 they feed. They are flat and depressed, and generally with 

 serrated margins in the mallards, and ducks, and swans, 

 flatter in the spoon-bills, and still broader in the pelicans. 

 With these forms of the bills and jaws, correspond especially 

 the forms of the digestive organs, and the claws of the 

 feet, as the analogous parts correspond with the forms of the 

 teeth in quadrupeds. 



From the length and varied uses of the tongue in birds, 

 the elements of the os hyoides are much extended longitu- 

 dinally, especially its cornua, or cerato-hyal portions, which 

 are often extended so far backwards that they rise upwards 

 behind the occipital bone, and arch forwards over the skull. 

 The lingual portions of the os hyoides, the basi-hyal, and 

 the glosso-hyal elements are also lengthened, like the tongue 

 and the whole face of these animals. There are in birds, 

 as in the inferior vertebrated classes, and as in some of the 

 mammalia, false ribs, anterior as well as posterior to the 

 true ribs. The ribs are here broad and compressed, securely 

 articulated to the vertebrae by their long head arid long 

 tubercle, and they have generaUy a process extending up- 

 wards and backwards from their posterior margin, especially 

 those placed towards the middle of the trunk. At their 

 vertebral extremity the ribs are compressed from before 

 backwards, so as to present their sharp edge to the cavity 

 of the trunk ; and at their sternal end they are compressed 

 in the opposite direction, so as to present their broad con- 

 cave surface to the interior of the body. The sternal ex- 

 tremities of the true ribs are united by cartilage to the ends 

 of the sternal ribs, or ossified sterno-costal cartilages ; and 

 it is at this articulation that ' the most extensive motions 



