176 



GENERAL ORNITHOLOGY 



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

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

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

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

 Below, it expands into two condyles (Gr. koVSuAos, hmdulos, a knob), 



^^^^3t 



Fig. 34.— Bones of a 'bird's right liincl limb : from a duck, Clangula islaitdica, i nat size • 

 Dr. E.W. Shufeldt, U.S.A. A, hip ; B, knee ; C, heel or ankle-joint, suffrago : D, bases of toes' 

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

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

 bases of toes ; in descriptive ornitliology (fe tarsus; often called " shank." Prom H outward 

 are the toes or digits, fin, femur ; ti, tibia, principal (inner) bone of leg ; fi, fibula, lesser 

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

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

 with three joints ; St, third toe, with four joints ; it, fourth toe, with five joints. At Others 

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

 tibia, which is therefore a tlUo-tarms, in part with the metatarsus, which is therefore a tarso- 

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

 to be, directly between tibia and metatai-sus. 



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 B; it 



