200 SPECIAL ANATOMY. 



one sublingual gland meets that of the other ; the posterior extremity and the 

 inferior border surround the ne.ro. Ungualis. 



The excretory ducts : 1, d. Bartholinianus opens upon the caruncula sub- 

 Kngualis, or unites with the duct. Whartonianus. 2. d.Riviani; from seven 

 to twelve small ducts open along the frenulum upon the mucous membrane of 

 the mouth, or are associated with the ductus Bartholin. 



Vessels: Artt. and Vv. are branches of sublingualis. 



Nerves: branches of ram. Ungualis trigemini with gang, sublinguak. 



431. 3. The teeth, dentes, mordices, are bone-like bodies, 

 fixed (per gomphosiri) into the alveoli of the jaws, thirty-two in 

 number (in the full-grown adult), consisting of a soft nucleus sur- 

 rounded by a hard, brittle, osseous substance (dentine) and the 

 enamel. The crown, corona dentis, projects freely into the mouth, 

 covered with enamel; the neck, collum,is a smaller portion sur- 

 rounded by the gums ; the root, radix, is fixed into the alveolus 

 (socket). Both the alveoli and the roots of the teeth are covered 

 with a delicate, highly vascular periosteum, which enters the 

 cavity in the interior of the tooth through a fine foramen at the 

 extremity of the root, and surrounds the nucleus. 



a. Incisor teeth, d. incisivi s. primores 



4 superior, 



4 inferior, 



in the centre, at the anterior part of the arcus alveolares. The crown is chisel- 

 shaped, convex in front, concave behind, the free edge sharp and broader 

 than the basis, which is thicker; the root is single (rarely double), conical, flat 

 at the sides, obtuse at the point. The superior incisors are stronger than the 

 inferior, the central (superior) stronger than the external. The superior 

 converge downwards; the external inferior diverge upwards. 



b. Corner, canine teeth, d. canini s. cuspidati, 



2 superior (eye teeth), 



2 inferior, 



the one by the side of the external incisors, are the longest, especially the 

 superior. The crown thick, irregular, conical, triangular, pointed; the root 

 longer (especially the superior) and thicker than the rest of the teeth, single. 

 The inferior canine teeth are received (when the teeth are closed) between 

 the superior canine and external incisors. 



c. Back, masticating teeth, d. malares. 



10 superior, 

 10 inferior, 



five upon each side, next to the canine tooth. The crown is short, almost 

 cubical, the free extremity quadrangular and uneven; root compound. 



We distinguish: 1. dent, molares minores ; these are the two anterior next 

 the corner teeth. Their crown is small, with two tubercles (bicuspid 'ati') ; 



4 superior, 

 4 inferior; 



