234 The Bird 
The deep serrations, however, are but indentations in 
the substance of the strong, narrow bill of the bird. 
When once in this saw-like grasp, the most slippery fish 
is helpless. The beak of the Shoveller Duck shows how 
well Nature has provided for its wants. The beak is 
arched and spatulate, while the sensitive epidermis is pro- 
longed at the edges into a series of comb-like teeth,— 
analogous to the whalebone in the mouth of a whale. 
Through this sieve the water is drained out, leaving 
entangled the edible worms and insects. 
If we should elevate our Shoveller Duck, placing him 
on long, slender legs and providing him with a corre- 
spondingly long neck, he would indeed be in a predica- 
ment, since only the tip of his beak could be brought 
to bear in feeding. Now a flamingo is really a long- 
legged duck, which feeds in much the same way as the 
Shoveller, and the difficulty mentioned is overcome in 
a most ingenious way. The mandibles are bent down- 
ward, almost at right angles, so that, when the head 
reaches the ground, not the tip but the whole inverted 
bill is in a position to sift out food. To meet the reversed 
condition, the lower mandible is deeply arched, instead 
of the upper as in the Shoveller Duck. 
We are able to follow the probable evolution of such 
remarkable beaks as those of the flamingo and skimmer 
by observing the growth of this organ in any individual 
from the time when the bird hatches from the egg until 
it is full-grown. In the very voung flamingo chick there 
is no sign of the subsequent deflection, the mandible 
being short, perfectly straight, and rather slender. As the 
