184 AVES (the bird) 



(3) Any filoplumes? 



(4) How are the body feathers arranged? 



(1) Of what use are feathers to the bird? To man? 

 (m) Pluck off the feathers. 



(1) Where is the skin thin? Where thick? 



(2) Can you find apteria, or spaces which did not bear 



feathers? 



(3) What difference is there in the size of the bird 



before picking and after picking? 



(4) Weigh the plucked bird. Compare this weight 



with that first found. What is the difference 

 between these weights, or the weight of the 

 feathers? 



(2) Scales. Do the scales overlap? Are the anterior and 



posterior scales alike? 



(3) Claws. 



(a) How do they unite with the toes? 



(b) How do they compare in color and texture with the 



covering of the toes and legs? 



(c) Use of the claws? Are they sharp and strong enough 



to be successful weapons of defense? 

 7. The Muscles. Skin the bird and expose the muscles. 

 Hold the skin up to the light. Do you see any blood-vessels? 

 What is their arrangement? Their use? Demonstrate (sepa- 

 rate out) the following muscles: 



(1) Those that move the wing as a whole. 



(2) Those that move the parts of the wing upon each other. 



(3) Those that move the neck. 



(4) Those that move the leg on the body. Bend the leg 



close up to the body and note the effect upon the toes. 

 What difference is there in the position of the toes 

 when the leg is straight from their position when the 

 bird is on its perch? 



(5) Those that move the parts of the leg on each other. 



(6) Those that move all the toes at once. 



(7) Those that move each toe independently. 



(8) Remove the muscles from the sternum, noting the 



blood-vessels and nerves which enter them near the 

 shoulders. 



