S6 Die TIONA RY OF BIRDS 



Birds — the Ostrich and its allies (as L'Herminier, we have seen, had 

 already shewn) exceiDted. But it was now made to a|:)pear 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 Gallinge, 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 gradu- 

 ally 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. This fact 

 was fastened upon by Geoffroy in his reply, which was a week later pre- 

 sented to the Academy, but was not published in full until the following 

 year, when it appeared in the Annates du Museum (ser. 3, ii. pp. 1-22). 

 Geofi'roy here maintained that the five centres of ossification existed in 

 the Duck just as in the Fowl, and that the real difi'erence of the 

 process lay in the period at which thej^ made their appearance, a cir- 

 cumstance, which, though virtually proved by the preparations Cuvier 

 had used, had been by him overlooked or misinterpreted. The Fowl 

 possesses all five ossifications at birth, and for a long while the middle 

 piece forming the keel is by far the largest. They all grow slowly, and 

 it is not until the animal is about six months old that they are united 

 into one firm bone. The Duck on the other hand, when newly hatched, 

 and for nearly a month after, has the sternum wholly cartilaginous. 

 Then, it is true, two lateral points of ossification appear at the margin, 

 but subsequently the remaining three are developed, and when once 

 formed they grow with much greater rapidity than in the Fowl, so that 

 by the time the young Duck is quite independent of its parents, and 

 can shift for itself, the whole sternum is completely bony. Nor, 

 argued Geoffroy, was it true to say, as Cuvier had said, that the like 

 occurred in the Pigeons and true 'Passerines. In their case the sternum 

 begins to ossify from three very distinct points — one of which is the 

 centre of ossification of the keel. 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. Cuvier seems to have acquiesced in the corrections of his views 

 made by Geoffroy, and attempted no rejoinder ; but the attentive and 

 impartial student of the discussion will see that a good deal was really 

 wanting to make the latter's reply effective, though, as events have 

 shewn, the former was hasty in the conclusions at which he arrived, 

 having trusted too much to the first appearance of centres of ossification, 

 for, had his observations in regard to other Birds been carried on with 

 the same attention to detail as in. regard to the Fowl, he would cer- 

 tainly have reached some very different results. 



In 1834 Gloger brought out at Breslau the first (and unfortunately 



