. A monograph of the genus Casuarius . i>.e. conjoined flexors digitorum is highly suggestive of a walking or climbing seems to be conceivable that the Ostrich branched off from the avian stem beforethe power of flight was perfectly established. The biceps oi Struthio arises from tlie siyina coracoidea and is inserted on to the radiusand ulna and the membrane between them. The extensor metncarpi radialis is ectej)icondi/lo-ulnaris is absent or fused with the extensor metaccirjri ulnaris. Theextensor digitorum communis supplies only the index. The two ^^onators form only
. A monograph of the genus Casuarius . i>.e. conjoined flexors digitorum is highly suggestive of a walking or climbing seems to be conceivable that the Ostrich branched off from the avian stem beforethe power of flight was perfectly established. The biceps oi Struthio arises from tlie siyina coracoidea and is inserted on to the radiusand ulna and the membrane between them. The extensor metncarpi radialis is ectej)icondi/lo-ulnaris is absent or fused with the extensor metaccirjri ulnaris. Theextensor digitorum communis supplies only the index. The two ^^onators form onlyone muscle. The fiexor digitorum suhliinis and jjrofundus arise by a single headfrom the flexor condyle of the humerus. The two muscles immediately divide; theupper part (:=sublimis) ends in two tendons, of which one is inserted on to (the) OF THE PAL/EOGNATH^ AND NEOGNATH^. 241 eat. fig. t^.e A.—Inner view of a dissection of the wing oi Rhea mneneana, to show the remains of the expausor sceund-ariorum and the ? proto-carin;ite condition of the flexor eurpi iihiaris. Note the large, fleshy inferiorportion eventually- inserted into the base of the 1st primary remex and the thin tendinous band whichruns along its free border, probably representing the iincuJum elasticinH. B.—Inner view of a dissection of the wing of Calodromas deijans. Note that the fleshy posterior portion ofthe carpi idnaria has become reduced to slender slips of muscle to the bases of the secondaryremiges, wliilst the vineulum elastieuiit has greatly increased in size to form a broad tendinous sheet. C.—Inner view of a dissection of the wing of Ojikthocomiis eristatus, showing another phase in the develop-ment of the vinciiJum elastkum and the persistence of a strongly developed posterior belly to the flexorcarj)! uhiaris. Numerous intermediate stages occur amongst the Neot/natluf.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbirds, booksubjectrat
