THE DEVELOPMENT OF THE SALIV.'UfY GLANDS IN MAN 57 



the mesenchyme, and from this spring the sprouts of the glands, which 

 are established successively in a craniocaudal direction until five are 

 present (Bujard). To some extent the furrow appears to be comple- 

 mentary to the elevation of the plica sublinguaUs. With regard to the 

 epithelial keel, whether antecedent to and conditioning the gland for- 

 mation, or merely the expression of their active proliferation and the 

 crowding of their anlages, sufficient data are not available to 

 determine. 



The submaxillary duct (p) opens upon the plica sublingualis towards 

 its mesal side, but separate from, and lateral to, the sulcus Ungualis 

 (Figs. 21, 22). The orifice is about 120 fi behind the frenulum on 

 the left ; on the right side the distance is 90 /j.. The duct bends 

 dorsad to its orifice almost at a right angle. It is then directed caudad, 

 with a slight inclination away from the oral epithehum as far as 

 the lingual crossing, where it sweeps in a wide curve ventrolaterad. 

 Immediately ventrad of the nerve the branches appear, surrounded 

 by a capsular thickening of the mesenchyme. As the mesal branches 

 are smaller and fewer than the lateral, the duct lies to the mesal side 

 of the bulk of the gland. It is situated also on its cranial aspect, as 

 is seen from the dominantly caudal direction of its branching. One 

 hundred and twenty micra distad of its attachment a lateral solid branch 

 is attached to the duct (Figs. 21, 23, /o), the greater sublingual anlage, 

 which, diverging laterad, terminates after a free course of 120 m. It 

 is solid throughout. Just opposite the lingual crossing the subma.xil- 

 lary duct is dorsoventrally flattened, gaining considerably in width, 

 and presenting a reniform section (Figs. 2 1 , 24, 72) . This configuration 

 obtains in four sections (120 fi). They are situated at the point where 

 the duct is about to pass ventrad and laterad from the embrace of 

 the mylohyoid muscle and the lingual ganglion — a point vertically 

 below the end of the lingual sulcus, which at this stage is devoid of a 

 postglandular flange. Of the two convex ends of the reniform 

 cross-section, the mesal continues into the descending portion of the 

 duct. The lateral in its last section appears dorsally, as well as ven- 

 trallv defined against the duct by a very slight incisure. It is highly 

 probable that this element represents the dorsal accessory submaxil- 

 lary of Huntington. The submaxillary duct of the left side contains 

 a lumen as far as the origin of the greater subhngual, where it is 



