214 Descriptive Zoology. 



to this brace there is an additional bone alongside of each 

 half of the wishbone, the coracoid bone, much stronger 

 than the collar bone itself. On the back the shoulder is 

 braced by the strong, curved shoulder blade. 



To strengthen the body for the work of flying, the verte- 

 brae of the trunk are consolidated, the only parts of the 

 spinal column that are flexible being the neck and the tail. 

 The Head and Neck. In many birds the beak is the only 

 organ capable of being used for grasping, hence the long, 

 flexible neck, which makes up for the above-mentioned 

 stiffness of the trunk. The bird must be able to reach the 

 ground, hence the length of the neck is proportioned to 

 that of the legs ; the head must also be able to reach any 

 part of the body. Some birds have as many as twenty- 

 four cervical vertebrae. In many birds the head must be 

 darted forward quickly to secure prey or in defense. The 

 horny beak is strong, yet light, and serves as a hand in 

 picking up small objects. Because of the quick motion of 

 a bird's head, as it picks objects out of the dirt, soft lips 

 would be too delicate. A head that requires such quick 

 handling needs to be light ; and in keeping with this re- 

 quirement there is an entire absence of teeth in all exist- 

 ing birds, though in a few cases rudiments of teeth are 

 found in the embryo. In the plucked bird it is found that 

 the neck is more slender than would appear from the out- 

 side, the feathers filling the angle between the neck and 

 the body, and making on the exterior a gradual transition, 

 where in the bare bird there is an abrupt change. 



The Pigeon's Food and Digestive System. Pigeons feed 

 chiefly on grains and other seeds. These are swallowed 

 whole, and pass into the crop, an enlargement of the gullet 

 situated in front of the breast. Here seeds are moisten* 

 and well soaked before they go farther. The crop serve 



