FORM AND HABIT: THE BILL. 31 
perform their toilet, and, pressing a drop of oil from the 
gland at the root of the tail, they dress their feathers 
with their bill. Parrots use the bill in climbing, and 
its hawklike shape in these birds is an unusual instance 
of similarity in structure accompanying different habits. 
Birds which do not strike with their feet may use 
the bill as a weapon, but the manner in which it is em- 
ployed corresponds so closely with the method by which 
a bird secures its food, that as a weapon the bill pre- 
sents no special modifications. In constructing the nest 
the bill may be used as a trowel, an auger, a needle, a 
chisel, and as several other tools. 
But as a hand the bill’s most important office is that 
of procuring food; and wonderful indeed are the forms 
it assumes to supply the appetites of birds who may 
require a drop of nectar or a tiny insect from the heart 
of a flower, a snake from the marshes, a clam or mussel 
from the ocean’s beach, or a fish from its waters. The 
bill, therefore, becomes a forceps, lever, chisel, hook, 
hammer, awl, probe, spoon, spear, sieve, net, and knife— 
in short, there is almost no limit to its shape and uses. 
With Hummingbirds the shape of the bill is appar- 
ently related to the flowers from which the bird most 
frequently procures its food. It ranges in length from 
a quarter of an inch in the 
Small-billed Hummer ( Micro- 
rhynchus) to five inches in 
the Siphon-bill (Docimastes), 
which has a bill longer than Spe 
its body, and is said to feed Shi imiapu “is 
from the long-tubed trumpet ee: 
flowers. The Avocet Hummer (Avocettula) has a bill 
curved slightly upward, but in the Sickle-billed Hummer 
(Zutoweres) it is curved downward to form half a circle, 
and the bird feeds on flowers having a similarly curved 
