ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1901.tb01754.x

出版商:Blackwell Publishing Ltd    

年代:1901

数据来源: WILEY

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1901.tb01755.x

出版商:Blackwell Publishing Ltd    

年代:1901

数据来源: WILEY

摘要:

SummaryBriefly, the result of this paper has been to show that the differences between the Palæo‐ and Neognathine palate are those of degree and not of kind.The Palæognathine is undoubtedly the older form. In it the vomer and pterygoid are uninterruptedly connected, one with another, throughout life; whilst the palatines remain permanently separated one from another caudad, and are connected only with the maxillo‐palatine processes distad.In the Neognathæ the vomero‐pterygoid relations are interrupted by the segmentation of the pterygoid distally; whilst the palatines, caudad, have moved inwards to meet in the mid‐ventral line beneath the distal ends of the pterygoids, with which they eventually fuse, and, distad, have lost their primitive connection with the maxillo‐palatine processes, and have established a new connection with the palatine processes of the premaxilla. The fusion of the distal ends of the pterygoid with the underlying palatine is accompanied by segmentation of the former and the formation of a pterygo‐palatine joint.In my recent memoir on the Palæognathaæ I inadvertently described the inward movement of the palatines as having resulted in “thrusting the vomer forwards” (p. 206). This is inexplicable, since it is obvious, from the very next sentence, that I had not lost Bight of the fact that this bone still retains its primitive connection with the pterygoid. That both pterygoid and vomer, however, have been affected by this movement there can be no doubt, since, as I have pointed out, in many cases it has brought about the suppression or atrophy of the hemipterygoid element, and has assumed the functions thereof by taking up the support of the vomer, as in the Anseres and Falconidse.The most primitive form of Avian palate is most certainly the Dromæognathous,not, as has been stated, the Schizognathous. The Schizognathous and Ægithognathous palates are both specialized forms derived by modification of the Dromæognathous type. The Desmognathous palate is a highly specialized condition which appears to have arisen independently amongst both Schizo‐ and Ægithognathous forms.The Neognathine palate is undoubtedly undergoing a further change, a change resulting in the transference of the support of the vomer from the pterygoid to the palatine. This has followed upon the movement of the palatiues from the origiual position outside the pterygo‐vomerine bar to a position beneath this. But the disturbance does not end here, for it is in the most highly specialized forms accompanied by the degeneration of the distal end of the pterygoid and

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1901.tb01756.x

出版商:Blackwell Publishing Ltd    

年代:1901

数据来源: WILEY

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1901.tb01757.x

出版商:Blackwell Publishing Ltd    

年代:1901

数据来源: WILEY