520 



THE TISSUES. 



point of the tongue each side of the fraenum, where five or six ex- 

 cretory ducts open close to the latter. 



All these glands are abundantly supplied with bloodvessels, each 

 of the caeca and vesicles being usually in contact with three or four 

 capillaries. Nerves also exist abundantly upon the excretory 

 ducts, and occasionally fine fibres are found in the glands them- 

 selves. 



The mucus, secreted by these glands, has already been described 

 (p. 198). 



2. The simple follicular glands are, when dissected out, 2 \ to \ of 

 an inch in diameter, and are found at the root of the tongue lying 

 under the mucous membrane, but above the mucous glands; and 

 so superficially that their position is seen externally. Indeed, the 

 excretory ducts of the mucous glands, before described, open into 

 the bottom of these follicles or sacs. Each of these is a cavity 

 lined by the mucous membrane of the tongue, with its papillae and 

 epithelium; with a number of large completely closed capsules ^\-$ 

 to J s of an inch in diameter, and with walls soW to Woo f an 

 inch thick, lying immediately under the membrane in a delicate 

 fibrous and vascular matrix. (Fig. 349.) Their contents are gray- 

 ish-white, consisting of a clear fluid, cells 4 oW to 24*0 o f an i ncn 

 in diameter, and free nuclei, 6 ^V^ to goW of an inch in diameter. 



Human follicular gland from the root of the tongue, a. Epithelium lining it. b. Papillae, c. 

 External surface of the follicular gland with the coat of connective tissue, e. Cavity of the gland. 

 /. Epithelium, g. Follicle in the thick wall of the gland. Magnified 30 diameters. (Kolliker.) 



These glands are abundantly supplied with vessels, forming close 

 networks upon the membrane of the capsules (Fig. 350), and then 

 proceeding to supply the papillae. Lymphatic vessels also proceed 

 from them (E. H. Weber), and nerves exist upon them. 



Of the compound follicular glands the tonsils are an example, 



