Organs of Nutrition 121 
fringed to correspond with the serrated or otherwise 
indented edges of the mandibles. One which is before me 
as I write is very elaborate. It is that of a wild Mallard 
Duck. At the tip is a thin, distinct flap or lamella, horny 
and with smooth edges. Behind it the tongue enlarges 
abruptly into a thick oblong mass, deeply grooved down 
Fic. 92.—Bill of Brown Pelican, showing extreme reduction of tongue in a bird 
which swallows whole fish. 
the center. The edges of the anterior half are fringed 
with a double line of horny hairs, while in the posterior 
portion the upper line is replaced with tooth-like struc- 
tures. The upper surface is smooth in front, but farther 
back two central folds arise and curve over laterally, 
forming tube-like grooves. Still more posteriorly, fleshy 
recurved teeth are visible, singly, in groups, or in regular 
lines. The tongue of our common barnyard duck is 
