MAMMALIAN ALVEOLINGUAL SALIVARY AREA 339 



raise the question of the possibility of the presence of a second gland 

 in this region, on the grounds of the difference in position of this anlage 

 in diflferent forms. He has in mind simply the abstract possibility of 

 an enlargement of one of the lesser sublinguals to such a size that, ex- 

 tending to a retrolingual position, it might be confused with a retro- 

 lingual (sublingualis major). It is remarkable that embryologists 

 have accepted or overlooked the two sites of origin of the subungualis 

 major with as much indifference as anatomists have the two sites of 

 the orifice of this gland. 



The alternative to the admission of two glands is to show that the 

 differences in the site of the anlages of the sublinguahs major are in- 

 essential, and, in particular, that its approximation to the submaxillary 

 is secondary. The evidence that this is the case in the pig will be 

 presented in detail {vide infra). Here it is desirable to note that the 

 condition of this anlage in Chievitz's earliest reported embryo is con- 

 siderably advanced, and that the stage of its inception is not covered 

 in his investigation. 



The results of Chievitz confirm the sagittal division of the alveo- 

 lingual gland field, already made on comparative grounds: mesal is 

 the submaxillary advancing along the Ungual sulcus ; lateral are the 

 lesser sublinguals (sulcus circumflexus) at first associated with a keel, 

 later opening diffusely upon the surface of the plica ; of intermediate 

 position and uncertain status is the sublingualis major, agreeing in 

 mode of development with the submaxillary, to which it may or may 

 not be attached, but if attached, yet retaining some independence in 

 the possession of a keel by which its advance is made. 



The remaining literature is concerned with the developmental pro- 

 cess exclusively. 



Hammar (oi) in a brief note records a submaxillary in a human 

 embryo of 13.2 millimeters as 



eine leistenformige Verdickung des Epithels, welche aboralwiirts am deutlich- 

 sten ist und hier etwas angeschwollen ungefahr in der Mitte der Rirme mit einem 

 stufenahnlichcn Absatz endet. Dies ist die Anlage der Gland, submax. 



Durch einem oralwarts fortschreitenden Abschnurungspr'ocess wird sie von der 

 Rinne losgetrennt, wobei aus der Stufe eine flaschen- odcr kolbenformige Anlage 

 des Drusenkorpers (Embryo 17 und 18.5 millimeter) aus der Leiste aber der lange 

 Driisengang hervorgeht. 



