THE DEVELOPMENT OF THE SALIVARY GLANDS IN MAN 



27 



voussoirs, the position wi 

 attached to the wall of the 

 it will be said to be parietal 

 peculiar in that a process 

 of folding affects the region 

 of the sulcus where their 

 sprouts are about to ap- 

 pear. The result is a blind 

 fold, or flange as we have 

 termed the structure, in 

 order to distinguish as 

 sharply as may be between 

 it and simple crests of pro- 

 liferation which play an 

 important role in the for- 

 mation of the ducts. The 

 flange involves the whole 

 thickness of the epithehum, 

 both basal and periderm 

 layers, while the crest is 

 composed of basal cells 

 alone. 



The sublingual gland of 

 the human adult has occa- 

 sioned anatomists consider- 

 able difficulty from a failure 

 at first to recognize, and 

 later to express in accurate 

 terms, the fact that it is a 

 complex resulting from the 

 enclosure in a single cap- 

 sule of primitively distinct 

 elements. The discovery 

 of the glandular mass hav- 

 ing long antedated the rec- 

 ognition of its several ducts, 

 the sublingual has come to 



11 be termed Jundal. When the plug is 

 sulcus, or if to the fundus, not at its crown, 

 in position. The large salivary glands are 



8 



Fig. I. Camera lucida outline of the oral 

 epithelium of a 20 millimeter embryo in frontal 

 section. Columbia Collection, No. 325. 



I. Buccal sulcus. 



8. Lingual sulcus. 



14. Alveolar sulcus. 



16. Intermediate sulcus. 



17. Tongue. 



18. Sublingua. 



19. Plica fimbriata. 



20. Alveolingual region. 



25. Palate process. 



26. Septum nasi. 



27. Nasal fossa. 



28. .Superior dental aniage. 



29. Inferior dental aniage. 



