SALIVARY GLANDS. 



425 



can be felt in the floor of the mouth, and 

 forms a prominent ridge which elevates the 

 mucous membrane. Its long axis is from 

 before backwards, following, in fact, the di- 

 rection of the horizontal ramus of the jaw, to 

 which the gland is applied. The inferior sur- 

 face rests upon the mylo-hyoid muscle ; the 

 external is received into the sublingual fossa ; 

 the internal is in relation with the genio- 

 hyo-glossus and hyo-glossus below, and the 

 mucous membrane above, the upper edge 

 being covered by the latter. It is shaped 

 somewhat like an almond, flattened from side 

 to side, having its large extremity anteriorly. 

 It is more compact in front than behind, in 

 which latter situation its component lobes 

 are occasionally separated the one from the 

 other, and exist under the form of distinct 

 irregularly rounded glands, with separate ex- 

 cretory ducts about a quarter of an inch in 

 length, coming from their upper surface. The 

 sublingual gland is from one inch and a half 

 to two inches in its long axis, three quarters 

 of an inch in the longest part of its vertical 

 diameter, and about a quarter of an inch from 

 side to side. It has a more granular feel, and 

 its lobules, which are mutually connected by 

 a very delicate areolar tissue, are more dis- 

 tinct, harder, and smaller than in either the 

 submaxillary or parotid. 



The ducts of the sublingual are very nume- 

 rous, and their orifices can be seen without 

 much difficulty, opening into the floor of the 

 mouth, behind the movable papilla of Whar- 

 ton's duct, and along the crest of mucous 

 membrane which is elevated by the upper 

 border of the gland from which they take 

 their origin. They are extremely thin and 

 delicate, and pour out, when pressure is made 

 on the body of the gland, a distinctly viscid 

 saliva. They range from one-tenth to one- 

 third of an inch in length, vary much in 

 their direction and relative situation, and are 

 in number from 7 to 15. The anterior are 

 very short, curve slightly on themselves from 

 behind forwards, are about four or five in 

 number, and some of them, according to many 

 anatomists, form a communication with Whar- 

 ton's duct, the remainder piercing the mucous 

 membrane of the mouth. The ducts from 

 the middle and posterior part of the gland 

 arise at unequal intervals from each other, 

 run in a parallel, divergent, or convergent 

 direction, and pierce the mucous membrane 

 by straight orifices, the posterior two or three 

 not being longer than the one-tenth or one- 

 eighth of an inch. They are known under 

 the name of the Ducts of Rivinus. Bartholi- 

 nus* has described another duct in connection 

 with the sublingual gland, and which some- 

 times proceeds from the accessory gland of 

 the submaxillary. It runs parallel to Whar- 

 ton's duct, and pierces the mucous membrane 

 by the side of it. It frequently opens, how- 

 ever, into Wharton's duct, and both terminate 

 by a common mouth. It is by no means 



* Caspar. Bartholin. Thorn, fil. deductu Salivali 

 hactenus 11011 descripto Observatio Anatomic a. 1G84. 



usually met with. In a young male, whose 

 salivary glands we recently dissected, the duct 

 of Bartholinus was very distinct ( a, fig. 139). 



Fig. 304.. 



I 



a a, tlie ducts of Bartholinus; bb, the ducts of 

 "Wharton ; cc, the inner surface of the sublingual 

 gland ; d, inferior surface of the tongue. 



It arose from a large lobe at the upper third 

 of the internal surface of the sublingual gland, 

 midway between its anterior and posterior 

 extremity. It was nearly equal in calibre to 

 the duct of Wharton, and was more than half 

 an inch in length, and opened on the left side 

 close to the orifice of that duct in the centre 

 of the loose papilla of mucous membrane. 

 The two orifices were so closely approximated 

 that it was difficult to determine their indi- 

 vidual identity. The duct of Bartholinus of 

 the right sublingual, on the other hand, al- 

 though arising from the corresponding part of 

 the body of the gland, anil being of the same 

 length and calibre, opened at the anterior part 

 of the crest of the mucous membrane, the 

 one-eighth of an inch behind the orifice of 

 Wharton's duct. 



The sublingual gland derives its arterial 

 supply from the sublingual branch of the lin- 

 gual, and the submental. Its nerves are de- 

 rived from the gustatory branch of the fifth. 

 Its lymphatics communicate with the deep 

 cervical glands. 



The salivary glands, according to the re- 

 searches of Huschke, are more voluminous, in 

 proportion to the bulk of the body, in the 

 infant than the adult, the submaxillary and 

 sublingual, however, being proportionately 

 larger than the parotid. In the adult, on the 

 other hand, the parotid is, in proportion to the 

 bulk of the body, larger than the other two. 



The subsidiary salivary glands. The labial, 

 buccal, molar, palatine, posterior, and interior 

 lingual glands may without any impropriety 

 be reckoned among the glands of the salivary 

 apparatus, being identical in their structure, 

 and provided with excretory ducts opening 

 on to the free surface of the mucous mem- 

 brane. Varying materially in size, and irre- 

 gularly rounded or flattened, they exude a 



