276 
POPULAR HISTORY OF BIRDS. 
birds whose habit^ as Derham^ calls it^ is ^^to quaffer and 
hunt in water and mud^^ for the numerous small and soft sub- 
stances which constitute the food of most of them. During 
this process^ in many cases mud and other extraneous sub- 
stances are collected, which, by the laminae, are separated 
from the edible matter, and strained off by the side. 
The wings are of moderate length : the trachea in the 
male is generally dilated, near the point of its division, into 
a bony chamber of various form, and some of the species 
have this tube prolonged and bent back in winding folds 
within the swollen keel of the sternum. The form of the 
bony chamber, and the extent and bending of the tube, 
vary in the different species, and must have a considerable 
connection with the intonation of the voice. The gizzard 
is large and muscular. Most of the species nestle on the 
ground, and lay numerous spotless eggs : the young as 
soon as hatched follow their parent, and are able to swim. 
It is only in the first group {Phoenicopterina), containing 
the Flamingoes, that the legs are of great length ; in the 
greater number they are rather short, and from their back- 
ward position and their webs, the birds when walking have 
an awkward waddling gait. In the second group [Fleciro- 
^ Physieo-Theology, p. 193. 
