SALIVARY GLANDS OF MAMMALS. 



407 



Sublingual glands, Human, nat. size, cxxv" 



have an irregularly triangular arrangement. The arteries and 

 veins that supply the submaxillary gland, are derived from the 

 facial and lingual. The nerves are from the mylo-hyoid branch 

 of the dental, and the gus- 

 tatory, but chiefly from the 

 submaxillary ganglion. 



The sublingual gland 

 forms a distinct eminence 

 underneath the anterior 

 part of the tongue by the 

 side of the fraenum. 

 shape and position 

 shown in fig. 305, c, c : 

 lobules are smaller, firmer, 

 and more distinct than those 

 of either the parotid or max- 

 illary : its ducts are nume- 

 rous, their orifices conspi- 

 cuous along the ridge of 

 mucous membrane behind the terminal papilla of the duct 

 of the submaxillary. Occasionally one duct is longer and 

 larger than the rest : it is named, after the anatomist who first 

 drew attention to it, * Bartholin's duct,' fig. 306, a. For a like 

 reason, Anthropotomy calls the duct of the submaxillary, ib. b, 

 6 Wharton's,' that of the parotid ' Steno's,' and the short ducts of 

 the sublingual ( Eivinus's.' The secretion of the latter gland is 

 more viscid than true saliva : and it may be considered as the 

 best defined of the subsidiary glands of the salivary system. The 

 posterior part of the sublingual is occasionally represented by one 

 or more distinct glands in juxtaposition, each furnished with a 

 very short excretory duct. The anterior lingual glands, fig. 307, b, 

 are situate below the apex of the tongue, between the lower longi- 

 tudinal and transverse muscular fibres, and emit their secretion 

 during the movements of that organ upon the mucous membrane 

 beneath the tip, by delicate ducts indicated by bristles in the figure. 



The labial glands form a series of closely packed small, dense, 

 spheroidal crypts, situated in the areolar tissue between the 

 mucous membrane of the mouth and the orbicularis oris muscle ; 

 their excretory ducts open upon the posterior or free surface of 

 the labial mucous membrane. They are not visible to the eye 

 when the lips are in their natural lax position, but when the 

 latter are everted, they appear as prominences upon the tense 

 mucous membrane. 



