Henry Gray (18251861). Anatomy of the Human Body. 1918.
between the globular processes forms the lower part of the nasal septum or columella; while above this is seen a prominent angle, which becomes the future apex (Figs. 45,46), and still higher a flat area, the future bridge, of the nose. The lateral nasal processes form the alæ of the nose.
FIG. 45 Head end of human embryo of about thirty to thirty-one days. (From model by Peters.) (See enlarged image)
FIG. 47 Head of a human embryo of about eight weeks, in which the nose and mouth are formed. (His.) (See enlarged image)
FIG. 48 Diagram showing the regions of the adult face and neck related to the fronto-nasal process and the branchial arches. (See enlarged image)
FIG. 49 Primitive palate of a human embryo of thirty-seven to thirty-eight days. (From model by Peters.) On the left side the lateral wall of the nasal cavity has been removed. (See enlarged image)
FIG. 50 The roof of the mouth of a human embryo, aged about two and a half months, showing the mode of formation of the palate. (His.) (See enlarged image)
Continuous with the dorsal end of the mandibular arch, and growing forward from its cephalic border, is a triangular process, the maxillary process, the ventral extremity of which is separated from the mandibular arch by a > shaped notch (Fig. 44). The maxillary process forms the lateral wall and floor of the orbit, and in it are ossified the zygomatic bone and the greater part of the maxilla; it meets with the lateral nasal process, from which, however, it is separated for a time by a groove, the naso-optic furrow, that extends from the furrow encircling the eyeball to the olfactory pit. The maxillary processes ultimately fuse with the lateral nasal and globular processes, and form the lateral parts of the upper lip and the posterior boundaries of the nares (Figs. 47,48). From the third to the fifth month the nares are filled by masses of epithelium, on the breaking down and disappearance of which the permanent openings are produced. The maxillary process also gives rise to the lower portion of the lateral wall of the nasal cavity. The roof of the nose and the remaining parts of the lateral wall, viz., the ethmoidal labyrinth, the inferior nasal concha, the lateral cartilage, and the lateral crus of the alar cartilage, are developed in the lateral nasal process. By the fusion of the