THE DEVELOPMENT OF THE SALIVARY GLANDS IN MAN 53 



to the postglandular flange (Fig. 13). This lateral crest is identical with 

 Chievitz's sublingual anlage, and the difference in its behavior on the two 

 sides of this- embryo may be related to the two conditions of the Bar- 

 tholinian duct in the adult, whether tributary to the submaxillary or 

 with an independent orifice of its own. These lateral or subhngual crests 

 have each an interruption in their cranial portion; on the right of 

 93 /i, on the left of 40 fi, in a total length for each of 240 /u from end 

 to end. A similar interruption occurred in the left submaxillary crest. 

 The interruptions in the crests reckoned by section counts may be 

 tabulated as follows : — 



Right Left 

 Fundal (submaxillary) crest . 



Length of interruption o 13.3 /x 



Distance from anterior end of crest — 40° H- 



Ectal (sublingual) crest : 



Length of interruption 93-i 1^ 4°° 1^ 



Distance from anterior end of crest 120.0 /* 120.0 ^t 



An ental crest, rather short and bulky, but of the same general 

 character as the others, projects mesad into the substance of the tongue, 

 with a slight inclination dorsad. The free angle is sUghtly thickened 

 (Fig. 12), but no free sprout has as yet appeared. From its position 

 in this embryo the anlage might be equally well assigned to the gland 

 of Nuhn-BIandin or of Weber. In older embryos (vide infra) an ectal 

 plug is attached to the lingual sulcus close to the frenulum, which 

 suggests that this anlage, like the others, advances craniad. It is there- 

 fore, on the whole, more probable that this sprout belongs to the apical 

 gland (Nuhn-Blandin) than to that of Weber. The crest in this em- 

 bryo (20 millimeters) is in the region of the lingual crossing (Fig. 12), 

 where the combined anlages present a triradiate cross-section. 



The minor differences in the flanges of the two sides appear in the 



following table : — 



Right Left 



Frenulum to lingual crossing 400.0 fi 400.0 fi 



Frenulum to sulcus lingualis 240.0^ 226.1 /a 



Frenulum to fundal llange (subma.xillary) 385.7 /x 332-5 /^ 



Frenulum to ectal flange (sublingual) 292.6 fj. 345-8 f^ 



Frenulum to ental flange 425-6 f* 4^5-6 H- 



Length of fundal flange (submaxillary) 172.Q // 240.0 m 



Length of ectal flange (sublingual) 240.0 // 240.0 " 



Length of free sublingual sprout 4°-° A* ^3-5 ^ 



Length of ental flange ii9-7 fi ii9-7 M 



Length of postglandular flange ..." 66.5 /a 1729 f^ 



