72 NATURE STUDY LESSONS FOR PRIMARY GRADES 



John's arm stretched out. Beside it picture the 

 dressed wing stretched out. What is this wing 

 mostly made of? (Skin and bones.) Can you think 

 of any reason why it may be well that there is no 

 more meat on it ? (The meat would make the wing 

 heavy. She would tire holding out a heavy wing in 

 flying.) 



But the hen has besides the skin, bones, and mus- 

 cles, what? (Feathers.) Do these help or hinder 

 her flying? (She spreads out these feathers and 

 strikes against much more air than the naked wing 

 could press against. She could not rise at all with 

 the naked wing.) Let us look at one of these large 

 wing feathers and see if we think it is the kind the 

 chicken needs for flying. Lift it. (It is so light 

 that I cannot feel its weight.) Does the chicken 

 need light feathers ? Why? Is this feather straight ? 

 (No, it curves downward a little.) Is this well? The 

 feathers hold the air under better than they would if 

 they were flat. [They will notice the difference in 

 pressure of a concave and a flat fan.] How many 

 of these long feathers ? Does it need so many ? 

 Pull a feather from this wing which I have here. 

 [The feather comes only after hard pulling.] Is 

 it well that the feathers are fastened so tightly ? 



