98 SALIVARY GLANDS OF LOWER PRIMATES 



lingual ridge, is present, in varying degrees of development, in all the 

 primates examined, constituting the most lateral component of the 

 entire group. It may be confined to the anterior part of the area, 

 lying altogether in front of the linguaUs intersection, or extend back- 

 wards towards the isthmian region, crossing the lateral aspect of 

 both submaxillary duct and lingual nerve. In certain forms (Nycti- 

 pilhecus and some Lemurs) its caudal extremity becomes continuous 

 with the isthmian series and thus reaches or actually joins the dense 

 mass of glandular tissue lodged in the soft palate. The greater sub- 

 lingual gland, when present, is closely associated with the alveolingual 

 mass, usually more or less imbedded in the same, but without paren- 

 cyhmatous continuity. Injection of the greater sublingual gland 

 through its own duct, or through the common terminal duct belong- 

 ing to it and the submaxillary gland, will always demonstrate its com- 

 plete structural independence of the lesser sublingual mass, no matter 

 how closely interlocked the two may be topographically. Usually 

 the greater sublingual gland lies embedded in the mesal surface of 

 the lesser sublingual mass, extending obliquely from the submucous 

 ventral border of the latter to the dorsal margin, beyond which its 

 terminal portion frequently projects. The presence of a well-devel- 

 oped greater sublingual gland seems to reduce, over the area of their 

 mutual contact, the development of the lesser sublingual acini, so 

 that the latter mass appears divided into a cephahc and caudal seg- 

 ment connected by a narrow intermediate portion, covering the lateral 

 surface of the greater subhngual. This condition is especially well 

 marked in the Macaques. On superficial examination in these forms 

 greater and lesser sublinguals appear to form a single and uniform 

 glandular mass. Differentiation of the latter by injection will, how- 

 ever, clearly reveal their mutual extent and relations. Occasionally 

 (e.g. Simla) the greater sublingual duct is so long that it alone lies in 

 relation to the medial surface of the lesser subhngual mass, the greater 

 sublingual gland proper being lodged below the latter's dorsal border, 

 directly on the mylohyoid. In only one instance (the specimen of 

 Troglodytes shown in Fig. 2) was the usual relation of greater and lesser 

 sublingual glands reversed, the former occupying a position on the 

 lateral aspect of the latter mass. This is, however, evidently an indi- 

 vidual variation, because in four other examples of the same ape, the 



