176 



GENERAL ORNITHOLOGY 



above and below. Above it has a globular head, «, standing off 

 obliquely from the shaft, received in the acetabulum (Lat. aceta- 

 hulum, a kind of receptacle) or socket of the hip, and a prominent 

 shoulder or trochanter, which abuts against the brim of the acetabulum. 

 Below, it expands into two condyles (Gr. koi'SuAo?, kondulos, a knob), 



J^^^3t 



Fig. 34. — Bones of a bird's right hind limb : fi'om a duck, Clancjula islandica, | nat. size ; 

 Dr. R.W. Shufeldt, U.S.A. A, hip ; D, Icnee ; C, heel or ankle-joint, snffrago ; D, bases of toes. 

 A to B, thigh or "second joint" ; B to C, cms, leg proper, "drumstick," often wrongly called 

 " thigh" ; to D, metatarsus, foot proper, corresponding to our instep, or foot from ankle to 

 basesTof toes; in descriptive ornithology J/iC tarsws ; often called "shank." From Z) outward 

 are the toes or digits, fm, femur ; tb, tibia, principal (inner) bone of leg ; /, fibula, lesser 

 (outer) bone of leg ; mt, principal metatarsal bone, consisting chiefly of three fused metatarsal 

 bones ; am, accessory metatarsal, bearing 1*, first or hind toe, with two joints ; 2t, second toe, 

 with tiiree joints; 3t, third toe, with four joints; it, fourth toe, with five joints. At C there 

 are in the embryo some small tarsal bones, not shown in the figure, uniting in part with the 

 tibia, which is therefore a tibio-tarsus, in part with the metatarsus, which is therefore a tarso- 

 metatarsus; the ankle-joint being therefore between two rows of tarsal bones, not, as it appears 

 to be, directly between tibia and metatarsus. 



for articulation with both the bones it meets at the knee. It is the 

 same bone as the femur of a quadruped or of man, and corresponds 

 to the humerus of the wing. In the knee-joint, many or most birds 

 have a small ossicle, and a few have two such bony nodules, not 

 shown in this figure, but nearly in the position of the letter £ ; it 



