THE SKELETON OF THE VERTEBRATE HEAD. 129 



orifice. The superior and middle turbinated folds of the 

 nasal chamber on each side are also supported by turbinated 

 cartilaginous projections from the internal surfaces of their 

 plates. 



I have already stated that the anterior fibre-cartilaginous 

 portion of the persistent part of the primordial cranium of the 

 bird enters into the structure of its vomerine sclerotome ; it 

 will now be observed that its posterior hyaline portion enters 

 into the formation of the ethmoidal sclerotome. In the 

 majority of birds the septal lamina continues cartilaginous, as 

 well as the greater part of the curved lateral plates, with 

 their internal turbinal projections. A more or less extended 

 portion only of each curved plate becomes ossified when it 

 extends inwards across the palate ; and the ossified portion 

 becomes anchylosed to the maxillary, or to the descending 

 maxillary process of the ethmoido-frontal (" nasal "), and in 

 many birds to the anterior extremity of the palate bone. 



I recognise, therefore, the posterior part of the nasal septum 

 as the centrum ; the so-called " nasals " as the meta-neurapo- 

 physes ; and the more or less ossified lateral and inferior walls 

 of the olfactory chambers as the neurapophyses of the eth- 

 rnoidal sclerotome of the bird. If it be objected to this 

 determination, that the parts which I consider as neurapo- 

 physes are only portions of the olfactory sense-capsules, I 

 would merely observe that these sense-capsules are in fact 

 combined with the neurapophyseal portions of the ethmoidal 

 sclerotome in the bird, as in the primordial cranium of the 

 mammal, reptile, and amphibian, and as in cartilaginous 

 fishes ; but that this circumstance in no way nullifies the 

 existence of the neurapophyseal element itself, either in the 

 sclerotome with which the olfactory capsules, or in those with 

 which the ocular and auditory capsules, are connected. I 

 would also observe that I base my determination of the 

 neurapophyseal character of these parts, not merely on their 



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