. The Encyclopaedia Britannica; ... A dictionary of arts, sciences and general literature. pisthocomus ^ the furculum is ankylosed with the manu-brial part of the sternum on the one hand, and with thecoracoids on the other. Ankylosis of the furculum withthe coracoids has also been observed in Didus,^ and withboth keel and coracoid in Fregata aquila (Shoulder-girdle and Sternum, p , 1; see also the actual specimenin the museum of CA. Surg. Eng.). The fore-limb of a Bird, when in a state of rest (fig. 33),exhibits a great change of position, if it be compared withthat of an ordinary Reptile;
. The Encyclopaedia Britannica; ... A dictionary of arts, sciences and general literature. pisthocomus ^ the furculum is ankylosed with the manu-brial part of the sternum on the one hand, and with thecoracoids on the other. Ankylosis of the furculum withthe coracoids has also been observed in Didus,^ and withboth keel and coracoid in Fregata aquila (Shoulder-girdle and Sternum, p , 1; see also the actual specimenin the museum of CA. Surg. Eng.). The fore-limb of a Bird, when in a state of rest (fig. 33),exhibits a great change of position, if it be compared withthat of an ordinary Reptile; and the change is of acharacter similar to, but in some respects greater, than thatwhich the arm of a man presents when compared with thefore-limb of a quadrupedal Mammal. The humerus liesparallel with the axis of the body, its proper ventral * Huxley On tlie Alecioromorpha, p. 306, fige. 8 and 9. • Owen On the Dodo, TraTU. Zeol. Soc, toL vi. part 2, p. 63,glate 20^ Sg.^. BIRDS 721 surface looking outwards. The fore-arm is in a positionmidway between pronation and supination, and the. Flo. of Fowls right wlrg. adalr. ntt. bIzp. A., hnmerne; r., radloe;u., nlnar; r., i/., radial and olaar carpal bODe« ; wltb the three dlgila I^1I.,1X manus is bent back upon the ulnar side of the fore-armin a position not of flexion but of abduction. In ordinary Birds the proximal end of the humerus isexpanded, and its articular head transversely ventral face is convex, and provided with a strongpreaxial ridge, which gives attachment to the pectoralmuscle. The proper dorsal face is concave from side , especially towards the postaxial margin, where thepneumatic aperture occurs in those birds which have thehumerus hollow. The distal end is expanded, and thearticular surface for the radius is a convex facet, directedobliquely inwards on its ventral face. In this respectthe Birds humerus exaggerates a feature of that of theLizards. In the Ratitoe tnese peculiarities
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