ORDER PALMIPEDES. 673 



sentinel. In consequence of this, the pursuit of them is ex- 

 tremely difficult. 



The wild ducks in general prefer the northern regions ; but 

 birds of such powerful flight can easily be supposed to pass 

 from one continent to another. We find, in fact, this same 

 species in corresponding climates in the New World ; but the 

 American species seems larger and more robust, though in 

 all other respects exactly similar. 



The ducks of the last subdivision in the " Regne Animal," 

 Sakcelles, which we may translate Teals, diifer in nothing 

 from the preceding but by being of a smaller size. Their 

 conformation, plumage, and mode of life are similar. As 

 game they are much esteemed, though their flesh is dry, 

 and difficult of digestion. They were domesticated by the 

 Romans, and probably might be so by us, if proper attention 

 were paid to their disposition, habits, and constitution. 



The last genus of the palmipedes is the Mergus (Mer- 

 ganser). The birds belonging to it live on lakes, ponds, 

 and rivers. They destroy a vast abundance of fish, and, for 

 their destructive powers in this way, have been compared to 

 the otters. It is for the purpose of retaining the slippery 

 fish that their mandibles and tongue are furnished with den- 

 til ations and papillae, which facilitate the entrance of food 

 into the gullet. So great is the bulk of the fish which they 

 sometimes swallow, that they cannot be introduced completely 

 into the stomach, the body descending there only when the 

 head is digested. The gizzard of these birds is less muscular 

 than that of the ducks ; their intestines and coeca are shorter; 

 the swelling part of the lower larynx in males is enormous, 

 and partly membranous. 



These birds, in swimming, hold the head alone out of 

 the water. They also dive to a great depth in search of 

 prawns ; and as the air which they have the faculty of accu- 

 mulating in the trachea permits them to remain some time 



VOL. VIII. X X 



