134 A GUIDE FOR THE STUDY OF ANIMALS 



Flight. 2. What is the shape of the body ? How is 

 the body made smooth ? To what is the shape and smooth- 

 ness adapted ? (Recall the appearance of a plucked pigeon 

 or chicken.) 



3. Observe the size of the wings by measuring their 

 width and spread (measured from tip to tip when out- 

 spread). Where on the body are they attached .? How is 

 this point of attachment advantageous .'' What is the shape 

 of the upper surface of a wing when spread .' of the lower 

 surface ? How is this shape advantageous in flight ">. 



4. Where are the largest and strongest feathers .-' How 

 are they arranged with respect to each other : (a) to pre- 

 vent air passing through on the down stroke of the wing .'' 

 (^) to permit folding .-' 



5. What is the shape and width of the tail when out- 

 spread.? when folded.? In what way does the tail as- 

 sist in flight .-' 



Walking and Perching. 6. Identify the parts of the leg 

 as in the frog. (See study of frog.) With what exoskele- 

 tal structures is each part covered ? How many toes are 

 there .? Does the pigeon walk on its foot or on its toes "i 

 Where is the ankle joint ? 



7. The bird's legs are arranged to support the body. 

 How is this brought about .' Compare with the lizard and 

 frog in this respect. 



8. Explain how the legs are adapted {a) to preserve the 

 balance of the body, and {b') for perching. Are they well 

 or poorly adapted for locomotion .? Explain. For what 

 other purposes are the legs sometimes used .' 



Feeding and Drinking. 9. What is the form and char- 

 acter of the jaws of the pigeon (called the beak).? Offer 

 food, and watch the pigeons eat. How does a pigeon seize 

 and swallow food ? Does it chew the food .? Locate the 



