78 SUBJECTIVE LESSONS. 
In what manner is the wing sexually adorned? How is 
it used as a musical instrument? How may it express 
emotion ? 
The Tail (Chapter II, pages 25-27).—Mention some birds 
in which the tail is sexually developed. What is the tail’s 
main office? Give illustrations of its relation to the char- 
acter of flight. What birds use the tail as a prop? De- 
scribe the tail of the Motmot. How may the tail express 
emotion? Give illustrations. 
The Feet (Chapter II, pages 27-30).—What relation ex- 
ists between the feet and wings? Give illustrations of the 
relation between the structure of the feet and the manner 
in which they are used. On what is length of foot some- 
times dependent ? Describe the Jacana’s toes? Of what. 
assistance are they to the bird? What birds use the feet © 
in seratching for food? What birds use the foot as a 
hand? Of what special use is it to the Birds of Prey ? 
Mention several species which use the foot as a weapon. 
Describe the seasonal modification in the feet of Grouse. 
The Bill (Chapter II, pages 30-34).—To what human 
organ does the bill correspond in use? Mention some of 
the functions of the bill. What is its most important 
office? What does the bill in effect become? To what is 
its shape in Hummingbirds related? Give illustrations. 
* What is a marked character of the bill of some fish-eating 
birds? How is the bill used by some shore birds? Give 
illustrations. Describe the shape and uses of the Huia- 
bird’s bill. 
CoLors oF BIRDs. 
Color and Age (Chapter III, page 36).—What is the 
character of the nest plumage of birds that run or swim at 
birth ? Of birds that are reared ina nest? Give illus- 
trations. What plumage follows the nest plumage? Does 
it resemble that of the parent? How long is it worn? 
Does the immature plumage sometimes differ from that of 
the adult? Give illustrations. When does the Bobolink 
acquire his full plumage? When, the Orchard Oriole ? 
Color and Season (Chapter III, page 37).—When the 
