SOME SUGGPJSTiO'NS FOR BIRD STUDY. 



addition, but reference to it is omitted for the sake of 

 simplicity, as the bird's wrist is reduced and cannot be 

 demonstrated as a " region " by the method of external 

 examination alone.) It is true that the bird's " hand " 

 looks very unlike the hand of man. In the bird the hand 

 is adapted for bearing the strong quill feathers of flight. 

 Two of the fingers have disappeared, two have become 

 united beneath the skin, and the third, the "thumb" 

 reduced in size, remains free. Eepeat the attempt to fold 

 the arm after the manner of a bird, and note now how the 

 thumb points outward from the hand. Examine the wing 

 at this place and discover the bird's thumb, feel close down 

 to the base so as to find the bone, and note the tuft of 



Fig. 26. The wing of the Pigeon, showing the bones and the principal feathers. 



feathers borne on this part. This tuft is termed the 

 " thumb wing." 



The teacher might here tell the story of the extinct bird 

 Archaeopteryx, which had separate fingers with claws as 

 well as feathers upon its wing; that the thumb of birds 

 often bears a claw, or that the fingers of the unhatched 

 ostrich are clawed. 



Examine again the outspread wing, feeling the skin 

 across the bend forming the elbow joint. This skin forms 

 a kind of web, giving an outspread surface enlarging the 

 area upon which the feathers are spread. Note the upper 

 and under coverts of this area, and also upon the upper arm. 



