THE PIGEON. 109 



4. Find the syrinx, or lower larynx, at the place 

 where the two bronchial tubes divide. The song of 

 the bird is produced in the syrinx. 



5. Inflate the lungs by means of a tube inserted 

 into the trachea. Are the lungs free, or attached to 

 the back? What holds them in place? What causes 

 air to go into the lungs? 



The SkuU. 



1. Separate the head from the neck, and scrape 

 as much flesh from it as you can. 



2. Find the large hole at the base of the skull 

 through which the spinal cord runs. This is the 

 occipital foramen. 



3. In front of the occipital foramen, find a round- 

 ish, convex knob or surface. This is the occipital 

 condyle. Is there one, or more than one? 



4. See how the lower jaw joins the skull. The 

 very small bone by which the lower jaw articulates 

 with the skull is the quadrate boiie. 



5. Find a slender bone along the lower edge of the 

 upper mandible. This is the jugal or maxillary bone. 

 Where is it attached at each end? 



6. When the lower jaw is depressed, what effect 

 does the motion have upon the quadrate bone? Upon 

 the jugal bone? Upon the upper mandible? 



7. Draw the skull, showing all the above men- 

 tioned parts. 



8. Separate two or three vertebrae from the neck. 

 Clean and draw them. 



The Nervous System. 



1. Find the spinal cord in the neck. Do you find 

 the roots of any nerves? 



2. Look into the body cavity, near the backbone. 



