ee 
7 
SUBJECTIVE LESSONS. 79 
male differs from the female, what seasonal change in 
color may occur? If the sexes are alike, is there much 
variation in color ? 
The Molt (Chapter III, pages 37, 38).—How are changes 
in a bird's plumage chiefly accomplished? Is the process 
of molting subject to much variation? What are these 
variations apparently dependent on? At what time of the 
year do all birds molt? What usually occurs the follow- 
ing spring? Do any birds have a complete spring molt ? 
Are special plumes ever acquired at this season? Describe 
the manner in which the Snowflake gains its breeding 
dress. 
Color and Food (Chapter III, page 39).—How is the 
color of Canaries sometimes altered? What is the effect 
of red pepper on fowls? What is sometimes fed to Par- 
rots to change their color? How do Flamingoes and Scar- 
let Ibises illustrate the relation between color and food ? 
What color does the Purple Finch become in captivity ? 
Color and Climate (Chapter III, pages 39-41).—How 
does climate affect the colors of birds? What does this 
demonstrate? How many races of Song Sparrows are 
known? What relation exists between their colors and 
the climate of the regions in which they live? Where are 
the extremes in color found? Are these extremes con- 
nected ? What is the prevailing character of the colors 
of Arizona birds? Of northwest coast birds? What are 
these races of birds? Under what conditions might they 
become species ? 
Color and Haunt and Habit (Chapter ITT, pages 41-44).— 
What is necessary to an understanding of the value of 
the colors of birds? What is the office of protective color- 
ing? What of deceptive coloring ? What are the prevail- 
ing colors of ground-inhabiting birds? Give examples. 
Are tree-inhabiting birds brighter than those that live on 
the ground? What explanation is advanced to account 
for this? How do we receive an erroneous idea of the col- 
ors of tropical birds? What has Mr. Thayer proved? 
What fact does he call attention to? How does this tend 
to conceal the animal? How does Mr. Thayer demon- 
