150 NATURE STUDY 



the solid white meat — muscle to move the wings ; the 

 wing which corresponds to the arm even having a rudi- 

 mentary thumb ; the knee, bending in the same direction 

 as our knee ; the ankle joint, with the heel; the long leg- 

 like foot ; and the tail bone. 



Method : 



Get from the children meat and chicken bones enough, 

 if possible, so that each child may have one of each for 

 comparison. 



The bones should be cleaned and broken, so as to show 

 their structure. 



Which are chicken bones ? Why do you think so ? 

 What other differences between these bones ? Have you 

 never seen a hollow bone in beefsteak or other red meat ? 

 What filled the opening ? Which bones are heavier ? 

 What advantage is it to the cow to have heavy bones ? 

 What disadvantage would they be to the birds ? 



Draw on the board the skeleton of a bird. Let the 

 children pick out such bones as they know — the wish 

 bone, wing, drumstick, breast bone, neck, back bone, ribs. 

 Let them see the use of each, and its analogy and homol- 

 ogy to the same bones in our own bodies. 



Feathers of Birds. 

 Facts : 



The feathers of birds are outgrowths from the skin, 

 differing from the scales of reptiles and the hair of the 

 mammals in character but not in origin. 



The parts of the feather are the quills, the shaft, the 

 barbs, and the barbules. The quill is hollow. The shaft 

 is filled with a light pith. The barbules are covered 

 with fine threads, usually hooked at the tip, thus fasten- 



