OSTEOLOGY OF LARIDJE. 601 



■with smooth, thickened, elevated edges, and a prominent overhanging articulating facet 

 on its supero-pos.terior border, for the trochanter major of the femur to rest upon. 



Femur.— This 'bone is exceedingly short, but quite straight (difiering greatly in this 

 respect from Puffams), and only moderately .stout. The shaft is nearly cylindrical, in- 

 clining above slightly inward toward the median line of the body, its lower extremity 

 presenting somewhat backward. Superiorly the bone expands into a large, thick, stout 

 trochanter, much elevated, and with a well-marked margin, which rises high above, 

 curves toward and slightly overhangs the head of the bone. From the inner side of this 

 trochanter the head projects directly inward ; there is no coustrictiou of the '-neck," 

 except 10 a very slight degree below; above, the articalar head of the Ixme is directly 

 continuous with a smooth concavo-convex space between it and the cirest of the troch- 

 anter. The shape of the articulating surface is such that it permits the head to sink 

 but slightly into the acetabular ring, the chief weight of the bird being borne by the 

 superior aspect of the trochanteric prominence, Avhich is accurately coaptatcd to the 

 overhanging abutment which projects from the superior margin of the acetabulum. 

 The fossa for the ligamentum teres is directly on the superior aspect of the head. The 

 whole outer aspect of the trochanter is rough for tendinous and ligamentous attach- 

 ments. 



The femoral condyles differ markedly in size and shape. The outer is the longest, 

 and very ranch the largest. The two are widely separated by a deep groove, whicli 

 runs up a considerable distance on the anterior face of the bone, and on the posterior 

 is continuous with the popliteal depression. The outer projects much the furthest out- 

 ward, downward, and especially backward. Its face, posteriorly, is divided by a longi- 

 tudinal groove. This groove receives the antero-posteriorly elongated head of the 

 fibula, forming the chief part of the femoro-fibular articulation ; while the ridge which 

 bounds the groove internally dips down into the space between the heads of the fibula 

 and tibia. The inner condyle has a broad, flat, oval face, which is applied directly to 

 the plane bead of the tibia. 



The two tibial crests are peculiar in shape and situation. The anterior of these is 

 short, but very high, rising as a thin, vertical lamina to quite an apex ; being trian- 

 gular, and nearly as high as long at the base. It is exceedingly thin, its sides perfectly 

 plane and vertical. Thp other crest is at right angles with the first ; looking directly 

 outward instead of forward, and having its side instead of base applied to the bone. 

 Its base is nearly identical with the base of the first, hut is at right angles with it. 

 The superior margins of these crests unite at their termination, and Ijoth rise above 

 the level of the head of the bone. The lateral crest being transverse to the line of 

 motion in the joint, forms a protecting wall or face in front of the joint, between the 

 margins of which, and the head of tl*e bone proper, there is a gentle and regular con- 

 cavity. The inner edge of the true head of the bone is directly contiouous with the 

 base of the anterior crest ; but between the outer edge and the extremity of the lateral 

 crest there is a deep notch. 



The head of the fibula is on the same plane with, and at the inner edge of, the head 

 of the tibia. It is narrowly oval, almost crescentic, its long axis antero-posterior. It 

 is only ligamentously connected with the tibia ; below, after a short space, it becomes 

 more or less completely anchylosed ; becomes again detached from the tibia, to finally 

 disappear a little below the middle of the bone. 



The tibial condyles, as usual, project further forward than backward. They are 

 much of the same size and shape, and on the same plane ; the inner, however, is less 

 stout and projects more, both inward aud forward. Posteriorly the condyles subside 

 into two acute ridges, having between them a smooth, laterally concave surface, ove" 

 which pass the extensor tendons. Above and between the two condyles on the anterior 

 surface of the bone, there is the ordinary fossa, partijUy converted by a bridge of bono 

 into a canalfor the confinement of the tendon of the extensor digifonim. 



The metatarsus is moderately long, contained 1-i times in the tibia. Its shaft is com- 

 pressed into a pretty regular quadrilateral shape, the lateral sides, however, remaining 

 a little convex. The tendons that go to the toes are mostly aggregated upon the ante- 

 rior aud posterior aspects of the bone. Above, the bone expands into a large, irregu- 

 lar head, widened- laterally for the reception of the two condyles, and posteriorly by 

 a short, high crest, into which is inserted the gastrocnemial tendon. This crest has also 

 several longitudinal grooves, deep and distinct, which conduct tendons to the toes. 

 The facets for the reception of the tibial condyles are merely two small subcircular de- 

 pressions near the edge of the bone, not differing much from each other in size or shape. 

 They are separated by a prominent process on the edge of the bone anteriorly on the 

 median line. The end of the bone is, as usual, divided into three heads, separated by 

 narrow but very deep sulci. Of these heads the middle is the largest, and directly in 

 the line of the bone ; the outer is placed a little higher up, but nearly in the same plane. 

 The inner, however, beside being much higher up, is placed far around toward the pos- 

 terior aspect of the bone. The articular faces of these heads present in a high degree 

 of perfection the peculiar shape by which extension of the toes at the same time 

 abducts them, and vice versd. 



