FIGURE 9 



A. Section through nasal region and lower jaw of 20 mm. human embryo. 



1, Septum nasi 5, Mandibula 



2, Paries nasi 6, Cavum oris 



3, Maxilla 7, Tongue 



4, Reichert's cartilage 



B. Chondrification of atlas. Section through atlas and epistropheus of a 20 



mm. human embryo 



1, Lateral masses of atlas 3, Body of epistropheus 



2, Anterior arch of atlas 4, Arch of epistropheus 



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