BIRD. 49 



Are the feathers essentially alike on all ' parts of the 

 body? Are all parts equally well covered? Pull out a 

 large wing-feather and notice the central axis or shaft sup- 

 porting the expanded portion or vane made up of small 

 side-branches (barbs), and these in turn having smaller 

 branches (barbules). Pull two of these barbs apart, watch- 

 ing with a lens to see the part played by the barbules. 

 Are the conditions the same at the base of the vane? Can 

 you find a downy feather among the others? Examine it 

 carefully and see how it differs from the quill described. 

 Pick the feathers from a part of the breast and study one 

 of the pin-feathers. What parts occur in it? 



Next pick the feathers from the whole bird. This will 

 be more easily done by dipping it in hot water. When 

 picking the feathers notice that they come from pits in the 

 skin. When the bird is picked, look for these pits. Are 

 they equally distributed on all parts of the body ; or are 

 they arranged in feather-tracts f 



In the leg see the thigh and shank (drumstick). Where 

 is the heel? Does the bird walk on the whole foot? Con- 

 necting the shank with the toes is the tarso-metatarsus. 

 How many toes? Do they all point the same way? 



INTERNAL STRUCTURE. 



Cut through the skin in the median line below from the 

 neck to the vent, being careful not to injure the deeper 

 structures in the neck. Pull the skin away. Insert a 

 blow-pipe in the mouth and innate. This will render the 



ries; and those on the arm, when they occur, are tertiaries. The 

 short feathers overlapping the large quills above and below are 

 the upper and lower wing-coverts. At the bend of the wing, just 

 outside the primary coverts, are short quills, borne on the thumb 

 and forming the false wing (ala spuria). 



