THE ENGLISH SPARROW. 



217 



quills) growing upon the part of the hand which corre- 

 sponds to the thumb. In the hollow beneath the wing, 

 at its junction with the body, is a tuft of long, loose, soft 

 feathers (the axillars). 



Expand the wing, and arrange all the feathers naturally. 

 Note the shape and curvature of the primaries and sec- 

 ondaries. Note their direction of overlapping. Find on 

 the wing a series of feathers which shingle in the oppo- 

 site direction. Observe the position of the coverts. See 

 how beautifully each feather falls into its proper place 

 when the wing is closed, how compactly the whole wing is 

 nestled against the sides of the body, and how it is over- 

 lapped by the other plumage, and made to contribute to 

 the symmetry of the bird. 



IV. The Legs. In. a 

 leg, find thigh, shank, and 

 foot. The foot consists of 

 a long, slender tarsus, and 

 four toes terminated by 

 horny claws. The tarsus 

 is made up of several tar- 

 sal bones solidly grown to- 

 gether (anchylosecT). Note 

 the directions the toes take, 

 and the number of joints 

 in each. What parts of the 

 leg are feathered ? What 

 parts covered by scales ? 

 What kind of a covering 

 has the lower surface of 

 the foot ? 



LEFT LEG OF SPARROW (from inner 

 side, slightly reduced) : fe, femur ; 

 fi, fibula; t, tibia; trs, tarsus or 

 tarsometatarsus ; ra, an incomplete 

 extra metatarsal at base of hind toe ; 

 1, 2, 3, 4, toes. 



Exoskeletal Modifications. In this external examina- 

 tion of the bird, three modifications of exoskeleton will 

 have been noticed. 



