6 
sometimes called the gape. The mandible or lower jaw is composed 
of two lateral halves, called ‘‘rami,’’ or branches, which are. 
separate behind, but united in front. A bird’s nostrils are two in 
number, usually situated near the base of the maxilla, where it. 
joins the forehead, but both their position and their form vary 
much in different birds. In the Petrels the borders of the nostrils. 
are prolonged forwards in a tubular form, hence their family is 
named ‘* Tubinares.’’ In some birds, as hawks and parrots, they 
open in a soft waxy looking covering of the base of the maxilla 
called ‘‘the cere.” In the Apteryx alone of existing birds the 
nostrils open near the tip of the bill, which may be 53in. long. 
We will now consider some of the specialities in bills. In the 
Toucan, Rhamphach toco, a tropical bird, the bill is very large in 
proportion to the size of the bird, but the bone is most delicately 
cellular, and combines strength with lightness like the pith of the 
elder, or the flinty skeleton of the sponge Fuplectella. In the Huia 
bird, Heteralocha acutirostris, the male and female have very 
different beaks. The male has a thick, somewhat conical beak, 
1iin. long, and the female 23in. long, sharp, thin, and pointed. 
Its favourite food is the grub of a timber-boring beetle, and the 
male bird with his short stout bill attacks the more decayed 
portions of the wood, and chisels out his prey, while the female 
with her long slender bill probes the holes in the sounder part, the 
hardness of which resists his weapon; or when he, having removed 
the decayed portion, is unable to reach the grub, the female comes. 
to his aid and accomplishes what he has failed to do. In many 
birds the maxilla is sharply hooked at the end, as in the Osprey 
and many Petrels. In the Crossbill, as the name implies, the ends 
of the beak are crossed, but not uniformly the same way, as many 
being crossed one way as the other. This bird is very clever with 
its peculiar beak in wrenching open the cones of fir trees to procure 
the seeds. Many bills are compressed, as in the Puffin, the 
Razorbill, and Australian Crane. Some birds have a straight 
strong bill, well shown in Woodpeckers; in some it is like a needle, 
‘ acicular,” as in humming birds, very often beautifully curved at 
the same time. In the Swordbill it is 3in. long, to enable the- 
birds to catch insects living at the base of a corolla of about the 
same length. The bill is ‘‘decurved”’ or bent down in the Curlew 
and the Whimbrel; “recurved”? or bent up in the Avocet and 
Godwit. In the ‘‘ Helmeted Hornbill”’ there is a great thickening 
‘of bone, and in addition a great mass of horn, being a solid. 
development of the horny sheath, but in the ‘‘ Rhinoceros Horn- 
bill” this projection is hollow. One class of birds, including the 
Goatsucker and the Swift, is remarkable for its wide gape, and is. 
called ‘* fissirostrate”’ or ‘‘ split bill.” In other instances the beak 
