THE DEVELOPMENT OF THE SALIVARY GLANDS IN MAN 



67 



the 22 millimeter embryo a plug is attached to the lingual sulcus a 

 short distance caudad of the frenulum. In his 10 weeks embryo Chie- 

 vitz describes a small plug arising from the lingual sulcus, but in this 



Fig. 27. Hypothetical schema of the derivations of the subma.\illary and greater 

 sublingual anlages. The ventral accessory submaxillary sprouts are omitted. 



g. Subma.\illary gland. 12. Dorsal accessory subma.xillary gland. 



10. Greater sublingual gland. 13. Secondary submaxillary gland. 



30. Lingual nerve. 

 The dotted lines in the course of the ducts of g, 10, and 13 indicate possible vari- 

 ations in the drainage of 10 and 13, whose ducts may be tributary to that of the 

 subma.xillary or acquire independent orifices. 



case from the lateral wall. Its direction is not stated, and it is men- 

 tioned in connection with the lesser subungual glands ; its identity 

 with the mesally directed plugs is more than cjuestionable. Of the 

 subsequent history of this element nothing is known. Its presence is 

 not recorded in Bujard's careful study of his 5 centimeter embryo. 

 That these sprouts represent the apical gland is only a conjecture, and 

 even the identity of the postfrenular plug with the mesal gland of the 

 lingual region lacks proof, although the resemblance of this to the 

 other flanges at 20 millimeters, is so striking as to suggest with much 

 probability the cranial shifting of its attachment in an analogous 

 manner. 



The lesser sublingual glands appear first in association with an epi- 

 thelial crest (Chievitz) , which is indented by a sulcus (circumflex) at 



