DEVELOPMENT OF THE PHARYNX AND NECK. 



35 



posterior border of the arch in front of it. It would be better, 

 perhaps, to describe them as distributed to the clefts rather than 

 to the arches. The anterior branch of the facial (nerve of the 



o nasal processes 



to max. proc. 



chorda tympani 



■2nd arch 



3rd arch 

 4th arch (sup. laryngeal) 



5th arch (recurrent laryngeal) 



Fig. 27.— Showing what become of the Nerves of the Visceral Arches, 



hyoid arch) is represented by the chorda tympani and great super- 

 ficial petrosal; that of the glosso-pharyngeal by its tympanic 

 branch (Fig. 27). 



AORTIC ARCHES. 



What become of the Aortic Arches — the Arteries of the 

 Visceral Arches. — In figure 21 is given the foetal arrangement 

 of the aortic arches, and in figure 28 the vessels in the adult 

 which are formed from them. The primitive aorta in the embryo 

 divides into two trunks, which run forwards along the floor of the 

 pharynx, one on each side, lying between the ventral ends of the 

 visceral arches. These may be termed the right and left ventral 



