But it was now made to appear that the struthious birds in this respect resembled, not only the duck, but a great many other groups - waders, birds-of-prey, pigeons, passerines and perhaps all birds not gallinaceous - so that, according to Cuvier's view, the five points of ossification observed in the Gallinae, instead of exhibiting the normal process, exhibited one quite exceptional, and that in all other birds, so far as he had been enabled to investigate the matter, ossification of the sternum began at two points only, situated near the anterior upper margin of the side of the sternum, and gradually crept towards the keel, into which it presently extended; and, though he allowed the appearance of detached portions of calcareous matter at the base of the still cartilaginous keel in ducks at a certain age, he seemed to consider this an individual peculiarity.
Notwithstanding this, to Gloger seems to belong the credit of being the first author to avail himself in a book intended for practical ornithologists of the new light that had already been shed on Systematic Ornithology; and accordingly we have the second order of his arrangement, the A y es Passerinae, divided into two suborders: singing passerines (melodusae), and passerines without an apparatus of song-muscles (anomalae) - the latter including what some later writers called Picariae.
Like Gloger, Sundevall in his ideal system separated the true passerines from all other birds, calling them Volucres; but he took a step further, for he assigned to them the highest rank, wherein nearly every recent authority agrees with him; out of them, however, he chose the thrushes and warblers to stand first as his ideal " Centrum " - a selection which, though in the opinion of the present writer erroneous, is still largely followed.
Macgillivray himself it was, apparently, who first detected the essential difference of the organs of voice presented by some of the New-World Passerines (subsequently known as Clarnatores), and the earliest intimation of this seems to be given in his anatomical description of the Arkansas Flycatcher, Tyrannus verticalis, which was published in 1838 (Ornithol.
Pp. 332- Keyserling 334) that, while all the other birds provided with perfect song-muscles had the " planta " or hind part of the and " tarsus " covered with two long and undivided horny plates, the larks (q.v.) had this part divided by many transverse sutures, so as to be scutellated behind as well as in front; just as is the case in many of the passerines which have not the singingapparatus, and also in the hoopoe.
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