The following year Ranzani of Bologna, in his Elementi di zoologia - a very respectable compilation - came to treat of birds, and then followed to some extent the plan of De Blainville and Merrem (concerning which much more has to be said by and by), placing the Struthious birds in an Order by themselves.
CASSOWARY (Casuarius), a genus of struthious birds, only inferior in size to the emeu and ostrich, and, according to Sir R.
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.
Some Hexapods which are very primitive in other respects happen to be also Apterous, but this cannot be held to prove that the possession of wings is not a primitive character of Hexapods (compare the case of the Struthious Birds).
As regards the struthious birds, they could not be likened to the duck, for in them at no age was there any indication of a single median centre of ossification, as Geoffroy had satisfied himself by his own observations made in Egypt many years before.
The Ratitae comprehend the struthious birds, which differ from all others now extant in the combination of several peculiarities, some of which have been mentioned in the preceding pages.
The fossil egg of a struthious bird, Struthiolithus, has been found near Cherson, south Russia, and in north China.