GLANDS OF THE ORAL CAVITY. 29 



regarded as an aggregation of simple follicular glands, while, 

 on the other hand, they are so widely different from the mucous 

 glands that they can on no account be classified with them. 



The simple follicular glands of the root of the tongue (fig. 

 169, /), form an almost continuous layer from the papilla 

 vallata, as far as the epiglottis and from one tonsil to the 

 other, lying immediately under the mucous membrane, and 

 above the mucous glands. Their position is so superficial, that 

 the separate glands are visible from without, like little eleva- 

 tions upon the mucous membrane, and allow their number and 

 arrangement to be recognised. When dissected out, we see 

 that each follicle is a lenticular or globular mass of J — 2'" in 

 diameter, invested upon its outer surface by the mucous mem- 

 brane, which is here very thin, lying loosely in the submucous 

 tissue and receiving upon its under surface the excretory duct 

 of a more deeply disposed mucous gland. In the midst of the 

 free surface a punctiform aperture, often tolerably wide (3 — J"'), 

 is easily perceived by the naked eye ; it leads into a funnel- 

 shaped cavity, which is remarkable on the one hand for its 

 narrowness, in relation to the size of the sac, and on the other, 

 for its thick walls, and is usually filled with a greyish mucous 

 material. 



Each follicle (fig. 181) is a thick-coated capsule, externally 

 surrounded by a fibrous investment connected with the deep 

 layers of the mucous 

 membrane ; internally, 

 it is lined by a process 

 of the mucous mem- 

 brane of the oral cavity, 

 with its papillge and 

 epithelium, and con- 

 tains between the two, 

 imbedded in a delicate, 

 fibrous, vascular matrix, a certain number of large, com- 

 pletely closed capsules or follicles (fig. 181, g), which 

 are about ~ — \" in diameter, round or elongated in form, 



Fig. 181. Follicular gland from the root of the tongue in Man : a, epithelium 

 lining it ; b, papillae ; c, external surface of the follicular gland, with the coat of con- 

 nective tissue ; e, cavky of the gland ; /, epithelium ; g, follicle in the thick wall of 

 the gland ; x 30. 



