32 



INTRODUCTION. 



there are always ten ; those belonging to the fore-arm are called 

 secondary, and their number varies ; the feathers, less strong, 

 attached to the humerus, are called scapular ; the bone which 

 represents the thumb has also certain quills called bastards. 



The bony tail is very short, but it has also a range of strong 

 feathers, which by spreading, continue to support the bird ; 

 their number is commonly twelve, but there are sometimes four- 

 teen ; in the gallinaceous birds there are eighteen. 



The feet have & femur, a tibia, and a peroneum, articulated to 

 the femur by a spring, whose extension is maintained without 

 effort on the part of the muscles. The tarsus and metatarsus 

 are represented by a single bone, terminated at the bottom by 

 three pulleys. 



Clutching Feet. 



Golden Eagle. 



Otprey. 



