THE DEVELOPMENT OF THE NOSE, AND OF THE PHAEYNX 

 AND ITS DERIVATIVES IN MAN. 



BY 



MERVIN T. SUDLER, Ph. D., M. D. 



Frojn the Anatomical Laboratory of the Johns Hopkins University. 



With 13 Text Figures. 



The presence of visceral folds homologous with the branchial arches of 

 the fishes and lower vertebrates, the progressively changing circulatory 

 system, the origin of the vertebrate mouth and its relation to the head 

 and brain have combined to make the study of this region one of the 

 most interesting and important divisions of mammalian embryology. 

 In fact a knowledge of the development of this region not only aids 

 us in understanding the adult anatomy but has been of the greatest 

 service in giving us facts upon which to base definite ideas in regard 

 to the evolution of these structures. There is scarcely a series of 

 phenomena anywhere in the whole science of embryology that better 

 illustrates the idea that "ontogeny repeats phylogeny '' than the de- 

 velopment of this region in the mammalia. 



Most of the work done on this region has dealt with the visceral 

 folds, the circulation and the origin of the thyroid and thymus glands, 

 and the exact form of the pharyngeal cavities have had comparatively 

 little attention, especially in man. The work of His' is especially 

 valuable. Hammar' has also studied this region in man. He recon- 

 structed the cavities and his work on the fate of the first branchial 

 pocket and the origin of the Eustachian tube is complete and exhaus- 

 tive. Piersol' has modeled the pharyngeal clefts in a complete series 

 of rabbit embryos. 



It seemed desirable to have a knowledge of the exact form of the 



iHis: Anatomie Menschlicher Embryonen. Leipzig, 1880. Also Beobaclitunffen 

 zur Geschichte der Nasen- und Gaumenbildun": beim menschlichen Embryo. Abhandl. 

 der math.-pbys. Classe der Konigl. Gesell. der Wiss., Bd. xxvii, No. iii, 1901. 



2 J. Aug. Hammar: Studien iiber die Entwickelung des Vorderdarms und einiger 

 angrenzenden Organe. 



'*G. A. Piersol: Ueber die Entwiclvelung der embryonaleu Schlundspalten und ihre 

 Derivate bei Siiugetbieren. Zeitscbr. f. wiss. Zool., Bd. 47, 1888. 

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