DIGESTIVE SYSTEM. 



139 



forms part of the maxillary arch, and finally most of 

 the upper jaw. In this manner the stomodeum 



Stomodeum. 



Nasal pit. 



'Lateral protuberance. 



Globular protuberance. 



Maxillary arch. 



^Mandibular arch. _ ^ ^ . ,, m _ 



Nasal process. 



Nasal pit. 



Lacrimal canal. 



Maxillary arch. 



Mandibular 

 arch. 



Fig. 100. Development of the face of the human embryo (His): 

 A, Embryo of about twenty-nine days; B, embryo of about thirty-four 

 days; C, embryo of about the eighth week; D, embryo at end of the 

 second month. 



becomes divided into an olfactory region and the 

 mouth cavity proper. The stomodeum at this stage 



