OF THE TEGUMENT ARY MEMBRANES. 1S1 



CHAPTER III. 



OP THE TEGUMENTARY MEMBRANES. 



238. These membranes are those which, internally as well 

 as externally, clothe the parts that are exposed to contact with 

 foreign substances. They are also called compound villous, 

 or folliculous membranes, on account of the numerous parts 

 which enter into their texture, and of the follicles which they 

 contain in particular. They constitute, next to the cellular 

 tissue, of which they are a modification, more or less com- 

 pound, the most universally extended tissue or organ in the 

 animal kingdom; they are the first parts that are distinct and 

 figured in the embryo; it is on them and by them that all the 

 rest, of the body is formed; in health during life, they are the 

 organs of the most essential functions; and it is in them and 

 by them that absorption and extensive secretion takes place; 

 it is upon them that all foreign substances produce impres- 

 sions ; they are often changed by disease; it is on them, in 

 fine, that most therapeutic agents are applied: their study then 

 is of the highest importance to the physician. 



239. Galen* had already remarked, that besides the ex- 

 ternal skin, which is the common tegument of all the parts, 

 there is a thin membranous skin which clothes the internal 

 parts; several anatomistst had already indicated the continua- 

 tion of the skin into some of the natural cavities, andj the 

 analogy of the mucous membrane with the epidermis; Bonn 

 had already described in detail, the continuation of the skin 

 with the internal membrane, into all the openings and cavities; 



* Of the therapeutic method, I. xiv. chap. 2. 



f Casserius, Pentaestheseion, hoc est, de quinque sensibus, liber. 



+ Glisson. De Guld,ventricub etintestinis. 



D* continuationibui, membranarum. 



