4 ANATID.E. 



genera, which will be pointed out in the description 

 of the species as they come in rotation ; it need only 

 be remarked here that the male usually furnishes us 

 with such construction : which is simple in the two 

 first stirpes of this family, as subsequently divided, 

 and, more or less, complex in the remaining three. It 

 may, nevertheless, be added, that those Ducks with 

 a simple hind toe possess a less complicated structure 

 of this organ than the Mergansers, or the Diving 

 Ducks with short wings ; and that, as far as expe- 

 rience teaches us, the variations of form to which this 

 part is subject are consistent with the habits of the 

 birds to which it appertains. 



The greater portion of the species prefer the fresh 

 water of lakes and rivers; others, and more especially 

 those that are furnished with the lobated hind toe, 

 affect brackish water and the sea-coasts. They usually 

 swim with great facility and much grace, many of 

 them plunging their heads under water, when search- 

 ing for their prey, while others submerge their entire 

 body at such times, and continue for a long period 

 beneath the surface of the water : they walk in a va- 

 cillating and embarrassed manner, those (as before 

 observed) with the lobated hind toe walking most 

 awkwardly, from having their legs placed more back- 

 ward on the body. These birds moult twice in the 

 year, and their feathers are of great utility to man, 

 as is the flesh of many of the species : their usual 

 subsistence consists of fishes, insects, vermes, mol- 

 lusca, vegetables, and seeds. 



There appear, as usual in all extensive groups 

 to be five types of form (which may be denominated 



