180 AVES (the bird) 



(4) Range of motion of the head? 



(5) Eyes. 



(a) Shape? 



(b) Size? 



(c) Position on the head? Why so placed? 



(d) EyeUds. Are there two or three to each eye? Raise 



the upper Hd and look in the interior angle for the 

 nictitating membrane. How does a bird wink? 



(6) Ears. 



(a) Shape? 



(b) Size? 



(c) Position on the head? 



(d) How protected? 



(7) Beak. 



(a) Length in inches? 



(b) Size? 



(c) Color? 



(d) Use? 



(e) Lips. Has the bird any lips? Why is this true? 



(8) Nostrils. 



(a) Number? 



(b) Position on the beak? 



(c) Openings. With a probe find out where the nostrils 



open into the mouth. 



(9) Mouth. 



(a) Tongue. Open the bird's mouth and examine the 



tongue. Describe it. 



(b) Glottis. Back of the tongue, find the glottis. What 



is its shape? What is its character? 



(c) Eustachian tubes. Pass a bristle through the tym- 



panum or ear-drum and see where it enters the 

 mouth. Is there one or two openings into the 

 roof of the mouth? 



5. The Neck. 



(1) Length? 



(2) Covering? 



6. The Exoskeleton. The feathers, claws, and scales form 

 the exoskeleton. 



