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 ia 

 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 5|iu. 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 Euplectella. In the Huia 

 bird, Heteralocha acutirostris, the male and female have very 

 different beaks. The male has a thick, somewhat conical beak^ 

 l-|in. long, and the female 2iin. 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 witli 

 its peculiar beak in wrenching open the cones of fir trees to procure 

 the seeds. Many bills are compressed, as in the Puffin, the 

 Eazorbill, 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 Sin. 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 



