256 MANUAL OF HISTOLOGY. 



The nmcosa is made up of delicate connective-tissue fibres, en- 

 closing in their meshes a series of lymph-spaces. Connective- 

 tissue cells are also found here, and some elastic fibres. There 

 are a few small papillae in the upper portion. The submucous 

 layer is thin, contains many elastic fibres, and is continuous 

 with the perichondrium. It contains the racemose mucous 

 glands, whose ducts open upon the surface. Some of the larger 

 glands are lodged in the depressions of the cartilage, and some 

 are even situated on its anterior aspects, their ducts passing 

 through to the posterior side. 



In the submucous tissue there are lymphatic follicles, some 

 of which are arranged about the mucous glands and their ducts. 



The membrane covering the false vocal cords, arytenoid 

 cartilages, and ary-epiglottic folds, as well as that lining the 

 ventricles and inferior compartment of the larynx is thicker 

 and more loosely attached to the subjacent parts. It is covered 

 by stratified columnar, ciliated epithelium, except upon the 

 edge of the false vocal cords and over the inner surfaces of the 

 arytenoids, where it is of the pavement variety. The mucosa 

 contains a large amount of lymphoid tissue, which holds in its 

 meshes lymphoid cells. Closed lymph-follicles are also found 

 in the submucous tissue of the false vocal cords and on the 

 floor of the ventricle. 1 That portion of the mucous membrane 

 which covers the true vocal cords is thin, more closely attached, 

 and has no mucous glands. In its anterior half it has numer- 

 ous small papillae (0.07 to 0.08 mm. in height, Coyne) project- 

 ing at the edge and on the superior and inferior surfaces of the 

 cord. They are composed of connective tissue, with many elas- 

 tic fibres. Their vascular supply is slight. The membrane in 

 this situation is covered by stratified pavement -epithelium, 

 continuous posteriorly with that which covers the inner sur- 

 faces of the arytenoids. Numerous racemose glands send their 

 ducts obliquely upward and inward to discharge their secretion 

 upon the upper and under surfaces of the vocal cords. 



In front of the corniculum laryngis, on either side, is a col- 

 lection of racemose glands surrounding the cartilage of Wris- 

 berg. Another collection is found between the arytenoids. 



The epithelium can be examined, either by scraping it from 

 the surface, or in sections. The mucous glands are best seen 



1 Coyne : Archiv. d. Physiologie, p. 92, 1874. 



