70 THE DEVELOPMENT OF THE SALIVARY GLANDS IN MAN 



(Chievitz, Bujard), but later they arise from the surface of this fold 

 and the floor of the alveolingual region (Chievitz, Hammar, Bujard). 



5. The massa subungualis is a topographical aggregate of a number 

 of distinct glands in a common connective tissue investment as is 

 clearly shown by the plurality of its ducts as well as by its develop- 

 mental history. Three components participate in its formation: the 

 greater sublingual (Barthohnian) gland, the lesser sublingual (Rivi- 

 nian) glands, and supramylohyoid lobules of the submaxillary. Of 

 these the lesser sublinguals alone are constant. 



6. The parotid and subma.xillary agree in mode of formation (Ham- 

 mar). In both a flange is formed; in both proHferation occurs at its 

 free angle and margin ; in both the duct is carried craniad beyond 

 the limits of the fold, by an advance of the proliferation along the oral 

 epithelium ; in both the duct is freed by a solution of continuity in 

 the flange. In tliis process remnants of the flange may remain at- 

 tached to the duct or to the oral epithehum ; these may serve as 

 starting-points for sprouts, the dorsal submaxillary and secondary sub- 

 maxillary respectively in the one case, the orbitoparotid in the other. 



7. The greater sublingual gland arises from the flange of the sub- 

 maxillary. It forms a crest of proHferation, its oriiice is shifted craniad 

 by the advance of the crest, and the duct is freed by constriction. 

 The apical gland has probably a like history. 



BIBLIOGRAPHY 



Bujard, Eug. iqii. Reconstruction plastique des glandes salivaires d'un foetus 



humaine de 10 semaines environ. Anal. Aiizeiger, Bd. 38, 4, 5. 

 Chievitz, J. H. 1885. Beitrage zur Entv.ickelungsgeschichte der Speichel- 



driisen. Arch. f. Anal. h. Physiol., Anal. .Ibt. 

 GoEPPERT, E. igo2. Die Entwickelung des Mundes und der Mundhohle mit 



Driisen und Zunge. Hertwig's Handbuch der Enlwickelitngsgcsch., Bd. 2, 



Th. I. 

 Hammar, J. .August, iqoi. Notiz iiber der Entwickelung der Zunge und der 



Mundspeicheldriisen beim Menschen. Anal. Anzcigcr, Bd. ig. 

 His, W. 1885. Anatomie menschlicher Embryonen. Th. 3. Leipzig. 

 Illing, G. 1904. V'ergleichende Makroskopische und Mikroskopische Unter- 



suchungen iiber die .Submaxillaren Speicheldriisen der Haussaugetiere. Ana- 



tomische Hefle. Bd. 26, Heft 2, 3. 



