How many nostrils? In which mandible are they located? Are they nearer the tip or the base of the mandible? (Fig. 284.) What is their shape? Do the nasal passages go directly down through the mandible or do they go backward? Is the inner nasal opening into the mouth or into the throat?
The beak or bill consists of the upper and lower mandibles. The outside of the beak seems to be of what kind of material? Examine the decapitated head of a fowl or of a dissected bird, and find if there is a covering on the bill which can be cut or scraped off. Is the mass of the bill of bony or horny material? With what part of the human head are the mandibles homologous? (Fig, 284.)
 | An image should appear at this position in the text. To use the entire page scan as a placeholder, edit this page and replace "{{missing image}}" with "{{raw image|First course in biology (IA firstcourseinbio00bailrich).pdf/389}}". Otherwise, if you are able to provide the image then please do so. For guidance, see Wikisource:Image guidelines and Help:Adding images. |  |
Fig. 284.—Skull of Domestic Fowl.
q, quadrate ("four-sided") bone by which lower jaw is attached to skull (wanting in beasts, present in reptiles; see Fig. 277).
Ears.—Do birds have external ears? Is there an external opening leading to the ear? In searching for it, blow or push forward the feathers. If found, notice its location, size, shape, and what surrounds the opening. There is an owl spoken of as the long-eared owl. Are its ears long?
The leg has three divisions: the uppermost is the thigh (called the "second joint" in a fowl); the middle division is the shank (or "drumstick"); and the lowest, which is the slender bone covered with scales, is formed by the union of the ankle and instep. (The bones of the three divisions are named the femur, tibiotarsus, and tarsometatarsus). The foot consists entirely of toes, the bones of which are called phalanges. Is there a bone in each claw? (See Fig. 285.) Supply the numerals in this sentence:
