ANATIB^ — CYGNIN^ : SWANS. 



681 



notice. They are salacious to a degree remarkable even in the hot-blooded, passionate class of 

 birds ; a circumstance rendering the production of hybrids frequent, and favoring the study of 

 this subject. If we recall the peculiar actions of geese nipping herbage, and of ducks " dab- 

 bling " in the water, and know that some species, as the mergansers, pursue fish and other live 

 prey under water, we have the principal modes of feeding. Nidification is usually on the 

 ground ; sometimes in a hollow tree ; the nest is often warmly lined vidth live feathers ; the 

 eggs are usually of some plain pale color, as greenish, drab, or creamy ; the clutch varies in 

 number, commonly ranging from half a dozen to a dozen and a half. The young are clothed 

 with stiffish down, and swim at once. Among the ducks and mergansers, marked sexual diver- 

 sity in color is the rule ; the reverse is the case with swans and geese. A noteworthy color- 

 ation of many species, "especially of ducks, is the specuhim; a brightly colored, generally 

 iridescent, area on the secondary quills. Most of the species are migratory, particularly those 

 of the northern hemisphere ; the flight is performed in bands, that seem to preserve discipline 

 as well as companionship ; and with such regularity, that no birds are better entitled to the 

 claim of weather-prophets. 



There are upward of 175 species of this family, inhabiting all parts of the world. They 

 dififer a good deal in minor details, and represent a number of peculiar genera aside from the 

 ordinary types, though none are so aberrant as to endanger the integrity of the group. It is 

 difficult to establish divisions higher than generic, because the swans, geese, and ducks, if not 

 also the mergansers, are closely united by intermediate genera. But the five groups presented 

 as subfamilies in the following pages, and representing the whole of the family, may be con- 

 veniently recognized, and are readily distinguished, so far as our species are concerned, by the 

 characters assigned. The genera will be found analyzed under heads of their respective 



subfamilies. 



Analysis (ff Sui/amilies. 



CYamiNM. Swcms. Lores partly naked. Tarsi reticulate. Hallux eimple. Sexes alike. 



AHSEEiira;. Geese. Lores feathered. Tarsi reticulate. Hallux simple. Sexes alike. 



Asa.t:ism. Miver Bucks. Lores feathered. Tarsi scutellate in front. Hallux simple. BUI flattened. Sexes 



unlike. 

 FuiiiGi7LiN.ffi:. Sea XMcks. Lores feathered. Tarsi scutellate in front. Hallux lobate. Bill flattened. 



Sexes unlike. 

 MEBQIN.S:. Mergwnsers. Lores feathered. Tars! scutellate in front. Hallux lobate. Bill cylindric. Sexes 



unlike. 



65. Subfamiry CYCNIN/E: Swan^. 



A strip 'of hare skin between the eye and bill ; tarsi 

 reticulate, and shorter tham middle toe and claw ; 

 hind toe simple, or with very slight lobe. In the 

 Swans, the neck is of extreme length and flexibility, 

 exceeding the trunk, with up to 22 or 26 vertebrae ; 

 the movements and attitudes on the water are pro- 

 verbially elegant and graceful. The bill equals or 

 exceeds the head in length ; it is high and com- 

 pressed at base (where sometimes tuberculate), flat- 

 ter and widened at the end ; the nostrils are median. 

 The lores are naked in the adults, though usually 

 feathered in the young. Some of the inner remiges 

 are usually enlarged, and when elevated in a pecu- 

 - Mute Swan, Cygnusolor. (From liar position of the wing, they act as sails to help the 



course of the bird over the water. The reticulate 

 tarsi are shorter than the middle toe and claw. The hallux is scarcely or not lobate. The legs 

 are placed rather far back for this family, so that the gait is awkward and constrained. The 



