8 HUMAN EMBRYOLOGY AND MOBPHOLOGY. 



accompany the nerves from the descending palatine. The nasal 

 nerve and anterior ethmoidal artery supply the process in Iron 



It will thus be seen that the chief nerves and arteries ol botn 

 processes are derived from structures in the spheno-maxillary 

 fossa. 



MAXILLARY PROCESSES. 



The Parts formed from each Maxillary Process.— The max- 

 illary process springs from the base of the mandibular arch and 

 sweeping forwards below the eye separates that structure from 



mid brain 



cerebral uesicle 



anterior nares 

 \ — upper Zip. mes. nas. proc. 

 eye 



premax. mes. nas. proc. 

 upper lip. max. proc. 

 alveolus max. proc. 



pafat. proc. 



max. proc. (section) 



inner recess 1st cleft. 

 (Eustach. tube) 

 posterior nares 

 'roof of pharynx 

 septal part, mes. nas. proc. 



Fig. 8.— Showing the ingrowth of the palatal plates of the two maxillary processes 

 early in the 2nd month. (After Kollmann.) 



the mouth (Figs. 1 and 2). In front it comes in contact and 

 fuses with the lateral nasal process which forms the outer wall of 

 the nasal cavity and with the globular process of the mesial nasal 

 which forms the premaxillary part of the palate and the middle 

 part of the upper lip. The part of the face formed by the max- 

 illary process is shown in figure 2. The hard palate (with the 

 exception of the premaxillary part), the soft palate and its muscles, 

 with the uvula, are formed by a horizontal plate which grows 

 inwards from the maxillary process and fuses with the plate of 

 the opposite side beneath the septum of the nose, with which 

 the horizontal plates also unite (Figs. 8 and 9). The palatal 



