BIRDS 



151 



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 backwaid? Is the inner nasal opening into the mouth 

 or into the throat ? 



The beat or bill consists of the upper and lower man- 

 dibles. 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 scrapea off. Is the 

 mass of the biU of bony 

 or horny matern ) .' With 

 what part of the human 

 head are the mandibles 

 homologous? (Fig 284.) 



Ears. — Do birds b ave 

 external ears ? Is tnere an external opening leading to the 

 ear? In searching fcr it, blow or push forward the feath- 

 ers. 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 sJiank (or "drumstick"); and he lowest, vhich 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 tarsometa- 

 tarsus). 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: 



Fig. 284. — Skull of Domestic Fowl. 



q, quadrate (" four-sided ") bone by which lower 

 jaw is attached to skull (wanting in beasts, pres- 

 ent in reptiles ; see Fig. 277). 



