198 ANIMAL ACTIVITIES. 
Where does the bird find the oil used in preening its 
feathers ? 
How does-the size of a bird’s egg compare with the 
size of its body? How does the size of a frog’s egg 
compare with the size of its body ? 
Are the senses of the bird keen or dull? Does the 
bird have the same senses as man? 
How would you describe the song of the bird you 
are studying ? 
The Wing. What is the shape of the wing? 
How many joints has it? 
Do you find bones corresponding to those of your 
own arm, forearm, wrist, palm, and fingers? Use a 
prepared skeleton of a wing. 
How many bones in arm, forearm, wrist, and palm ? 
How many fingers? Is there a thumb? Sketch the 
skeleton of the wing. 
Does the skeleton of a frog show a similar structure 
of the arm? How does the arm of a turtle compare 
with the wing of a bird?. 
Do you find feathers on the thumb? on the hand ? 
on the forearm ? on the arm? 
The Leg and Foot. Do you find thigh, shin, ankle, 
foot, and toes? Where is the heel? Sketch the 
skeleton of the leg. 
How many toes? Do all the toes point in the same 
direction ? 
Are there feathers or scales or both on the tarsus ? 
When scales are present what is their shape ? 
Are there webs between the toes? 
In a fresh specimen can you find the tendon which 
moves the toes? How do the toes act in perching ? 
Feathers. Obtain some large feathers from the 
wing or tail of a pigeon or a barn-yard fowl. Notice in 
a single feather the shape as seen in outline. Do you 
make out the shaft and the vane? Sketch a feather. 
Can you separate the parts of the vane into branches 
of the shaft (barbs) ? 
