' Song Birds and Water Fowl 
cant variety of physical types to be found 
among them. It is true, there are some differ- 
ences in form and figure among the various 
land groups, and these differences become still 
more evident upon prolonged acquaintance. 
Yet the ‘‘ build’’ of all the land birds is vastly 
more uniform than that of water birds, whose 
variety of appearance, even to the most careless 
observer, is very striking. We have strong 
proof of this greater variety in type among 
water birds in the fact, first, that while the 
land birds of North America, comprising two- 
thirds of the entire avifauna, are arranged in 
six orders—which, in the main, conform to 
the most conspicuous differences in figure—the 
water birds, only half as numerous, are divided 
into seven orders. But this expresses only a 
small part of the truth. For, not only are the 
six orders of land birds far more nearly uni- 
form in figure than the seven orders of water 
fowl, but the vast majority of all land birds 
usually seen by the field ornithologist belong to 
only two or three orders, wherein, too, the 
differences of type are quite inconspicuous ; 
while the greatest departure from the general 
type is among a small number that are com- 
paratively infrequent. 
§2 
