THE DEVELOPMENT OF THE SALIVARY GLANDS IN MAN 59 



duct and its larger branches it is well defined ; the walls are composed 

 of two layers of low epithelial cells. 



The greater sublingual gland arises from the submaxillary duct 

 near the angle wliich it makes as it approaches its orifice. The duct 

 extends caudad in close relation to that of the submaxillary to ter- 

 minate in two buds, one of which shows e\adence of secondary sprout- 

 ing. The wall of the duct is composed of two layers of ci)ithelial 

 cells ; the lumen extends to the terminal buds. 



The lesser sublingual glands, five in number, are attached to a deep 

 epithelial crest directed ventromesad. They diminish in size cranio- 

 caudad. All of these anlages are solid and appear as continuations 

 of the basal cells of the epithehum, which is indented by a sulcus along 

 the attachment of the epitheUal keel. A few isolated sprouts are 

 found farther caudad, springing from the surface of the epithelium, 

 unattached to any crest ; these Bujard designates, rather infelicitously, 

 difl'use buccal glands. 



18. Chievitz. Embryo of 12 weeks. A well-developed plica sub- 

 lingualis extends from the palatine arch to a point craniad of the 

 frenulum. The orifice of the subma.xillary is situated on the mesal sur- 

 face of this fold o. 1 2 millimeter cranial to the frenulum. In point of 

 outward form and topography the gland has attained essentially the 

 adult condition. A tjqjical greater subhngual gland occurs on the 

 left side. From the submaxillary duct, immediately caudal to its 

 orifice and from its lateral side, a smaller duct arises, which after a 

 course of i millimeter forms a small gland with sprouts of the second 

 order, in the unaltered mesenchyme ventral and lateral to the duct 

 of the submaxillary. On the right there was no trace of tliis element. 

 On each side are found 11-13 lesser sublingual glands, solid plugs, for 

 the most part unbranched, set in a row at intervals of about 1.5 milli- 

 meters, the first of the series lying immediately craniad of the sub- 

 maxillary. They are attached to the apex and lateral surface of the 

 plica subhngualis and no longer are related to any sulcus ; their sprouts 

 are lateral to the submaxillary and greater sublingual glands, and not 

 in contact with the latter. 



19, 20, 21. Zumstein. Fetuses of 6, 8, and 9 months. The alveo- 

 Hngual region was studied in serial sections. In all the greater sub- 

 lingual is lacking. The lesser sublinguals extend caudad into the arcus 



