418 NATATOHES. 



with its edges toothed ; the wings are of moderate length. The 

 males have, for the most part, the wind-pipe enlarged into a bony 

 chamber, varying in form and size; sometimes this tube is much 

 prolonged, and bent back in folds within the swollen keel of the 

 breast bone, peculiarities of organization probably connected with 

 the loudness of the voice. The gizzard, especially in the land 

 species, is large and muscular. 



The Ducks mostly build their nests upon the ground, but some 

 on trees, and lay numerous unspotted eggs. The young are at 

 first covered with soft down, and can run and swim as soon as 

 they leave the shell. The laminated structure at the edges of 

 the mandibles, (Plate IX. fig. 5,) has often been referred to as 

 showing special adaptation to the habit of feeding in birds of this 

 family, enabling them to take with facility minute animals which 

 swarm in rivers, and those equally numerous found on the sides 

 of rivers and inland streams. By means of their broad beak, 

 they capture at one effort, considerable numbers, and as they are 

 drawn forth, covered with mud, this offensive part is thrown out 

 between the interstices, or tooth edges of the mandibles, (Plate 

 IX. fig. 5,) which, however, are not sufficiently wide to allow of 

 the passage of the insect food at the same time, so that the beak 

 operates as a sifter, expelling the refuse, but retaining the food. 

 It is probable that the large and fleshy tongue is an assistant in 

 this separating process. 



GEESE seem to form the connecting link between the Swim- 

 ming and Wading Birds, retaining as they do the manners of the 

 Waders, but walking much more than they swim. Their food 

 consists more of grains and insects than of fishes; their legs are 

 long, arid they have a considerable space above the tarsal joint. 

 These birds, in common with the SWANS, have rather long necks. 



The TRUE DUCKS include a large variety of species and are 

 found in almost every part of the world. 



TheSnovELER, or SPOON-BILL, A. clypeata, (Lai. furnished with 

 a shield.) is in length from seventeen to twenty inches ; it is 

 named from its broad, shovel-like bill. Usually it breeds far 

 North, but to this there are exceptions. Some think its flesh ex- 

 ceeds that of the Wild Duck. 



The MALLARD, or WILD DUCK, A. loschos, (Gr. loslas, a mal- 

 lard, from boske, a pasture,) is the parent of our domestic broods. 

 The ordinary length is about two feet, but one variety is said to 

 measure thirty inches. Its flesh is much esteemed. Richard- 

 son says " the Widgeon or Wild Duck is a strange eater of 

 grass ; " to this the specific term refers. 



The SOFT-BILLED SHOVELER, Malacorhyncus, (Gr. mafakos, 



