OF THE MUCOUS MEMBRANE. 191 



mucous membrane, discovered by Hunter, in fistula in ano. 

 At its orifice in the skin, if it terminates on that surface, the 

 mucous canal of the fistula, to a certain depth, has a distinct 

 epidermis, which is continued with that of the skin. 



SECTION II. 



OF THE MUCOUS MEMBRANE. 



260. The internal tegumentary, or mucous membrane has 

 received the latter name, at first in the nasal fossae (^v|a, nos- 

 trils) on account of the mucus (pvfr pituita] it produces. It 

 constitutes a humid tegument that clothes all the cavities com- 

 municating externally, all of which receive or eject foreign 

 substances. Regarded at first as the particular internal mem- 

 brane of each hollow organ, and having no other name, after- 

 wards called, villous or fungous, pulpy, porous villoso-papilla- 

 ry, in the alimentary canal, pituitary, or mucus in the nose 

 and throat, anatomists were not long in discovering follicles in 

 nearly all its parts, which caused it to receive the generic ap- 

 pellation of glandular, and in remarking the resemblance of 

 the nasal and intestinal mucus, to the unctuous humour of the 

 trachea and bronehiae, and even the analogy of mucus to the 

 epidermis; from this moment the identity of the various parts 

 of this membrane was known. Pathologists, M. Pinel in par- 

 ticular, had already remarked this in treating of catarrh. No 

 general and satisfactory description of this membrane, how- 

 ever, had been given until that of Bichat.* Anatomists and 

 pathologists, have since generally agreed in adopting his ideas 

 on this subject, Gordon excepted, who finds too many essential 

 differences between the various mucous membranes, to include 

 them in one common description. 



261. The mucous membrane forms an internal tegument 

 to all the cavities that open externally; its more important por- 

 tion clothes the whole alimentary canal from the mouth to the 



* TraiM det membranes. Paris, an. viii. 

 26 



