THE DEVELOPMENT OF THE SALIVARY GLANDS EST MAN 49 



The formation of this tube is attributed to a bridging over of the 

 lingual sulcus by coalescence of its walls. 



4. Sudler. Embryo CLXIV, N.B. 12, V.B. 14. Probable age 

 5 1 weeks. The anlage of the subma.xillary is "simply a rounded rod 

 of cells staining deeper than the surrounding tissues." It is repre- 

 sented ('02, Fig. 8) as projecting at an acute angle from the Ungual 

 sulcus, with a blunt, but not enlarged, extremity. 



5. Chievitz. Embryo of 14 millimeters length, after preservation in 

 spirits. Age 6 weeks. The tongue is bounded by a sulcus which 

 deepens caudad. From this the plughke subma.xillary extends 104 /i 

 ventrad. The anlage is a little larger on the left side. The plug is 

 cranial to the plane of the angulus oris, 560 /* from the frenulum ; 

 immediately craniad of it the Ungual nerve crosses the lingual 

 sulcus. In Fig. 6 B, which is taken from a graphic reconstruction, 

 the sulcus Ungualis is given a peculiar slope, owing to Ms assumption 

 that the roof of the mouth formed a straight horizontal Une in median 

 section. The rodUke submaxillary projects from the sulcus, forming 

 with it in front an obtuse angle, which justifies the assumption that 

 an acute angle would have been made behind the anlage, had he 

 kept his sulcus straight. The oral epitheUum was lost in this embryo 

 except for a plug (EpithelpfropJ) in the anlage. 



6. Paulet. Embryo of 14.7 milUmeters length, V.B. The anlage 

 of the submaxillary is soUd and comprises a ridge corresponding to the 

 duct, and a round bud which represents the body of the gland. The 

 anlage of the duct is about twice as long as that of the body ; together 

 they have a length of 800 fi. The central cells of the bud are more 

 voluminous and stain less intensely in carmine than the peripheral 

 ceOs. The body is still attached to the oral epitheUum. 



The agreement of Chievitz, Hammar, Sudler, and Paulet, taken 

 together with the perfect objectivity of their descriptions, must be 

 held to establish the soUdity of the anlage and outweigh His's state- 

 ment that it is a tube. As has been said, the anlages of the saUvary 

 glands quite uniformly present sections in which the centers of the 

 ducts and sprouts are more faintly stained than the basal cells. In 

 running over thick sections with a low magnification, it is easy to mis- 

 take the pale center for a lumen. 



A comparison of the triangular anlages of Hammar and Paulet 



