136 PRIMATE. ALVEOLINGUAL SALFVARY AREA 



tion by turning dorsomesad into the anterior faucial pillar and beyond 

 into the soft palate. 



2. The medial glandular line, on the other hand, swings caudo- 

 laterad, intersecting the preceding alveo-isthmian-palatine hne at an 

 acute angle and escapes from the confines of the oral cavity proper, by 

 extending Taeyond the caudal margin of the mylohyoid into the digas- 

 tric interval of the submaxillar}' fossa which permits of the freer un- 

 folding of the main secretory salivary glands. 



Figure 10 shows in schema the topographical dixisions of the alveo- 

 hngual area. 



On the left side the prclingual area cephalad of the linguahs nerve 

 is shown divided into three glandular groups, I. II, III, by coronal 

 cleavage hues. The lingual area (IV) corresponds to the lateral con- 

 striction effected by the lingual nerve. Caudad of this point the 

 glandular elements of the posllingual or isthmian area (V) turn dorso- 

 mesad into the anterior faucial field and soft palate to become con- 

 tinuous with the glands of the palatine (VI) and pharyngeal areas 

 (VII). 



The right side of the same figure shows the developmental plan 

 usually followed in mammals, characterized by retention of separate 

 single glands along the lateral (j) and to a much less degree along 

 the medial {4, 4') border of the field, while the intervening area gives 

 rise to the ducts of the submaxillary (/) and greater sublingual (2) 

 glands, whose bodies, extending beyond the mylohyoid border into 

 the digastric interval of the submaxillary fossa, find here greater 

 opportunity for developing the secretorj- portion of the salivary 

 apparatus. 



