OF THE TEGUMENTART MEMBRANES IN GENERAL. 185 



intermediate gradations. We only find some suddenly marked 

 differences, in parts closely approximated, but whose func- 

 tions are very different, as between the oesophagus and the 

 stomach, the vagina and the uterus; but even there as well as 

 every where else, they are only varieties, which easily reduce 

 themselves into a unique type of organic texture. 



245. The teguments have a free and an adhering sur- 

 face. The first is turned outwards for the skin, and inwards 

 for the mucous membrane; it is the inverse with the second. 

 The adhering surface corresponds to the mass of the body 

 and to the cellular tissue generally. This tissue [139] 

 forms there a layer more or less dense, more or less thick; 

 in other places it is the ligamentous tissue, or the fibrous elas- 

 tic tissue which lines the teguments; in a considerable por- 

 tion of their extent, they are lined with muscular fibres. 



246. The tegumentary membrane, besides the great ap- 

 pendages and excretery ducts of the glands of which we have 

 spoken [242], has an innumerable multitude of other depres- 

 sions, more simple and a great deal smaller, that have been 

 called follicles, loculae, lacunae, crypta, simple glands, &c. 

 These follicles,* at first observed and described in some points 

 of the teguments by various anatomists, and afterwards in 

 all the parts by Malpighi, Boerhaave, Kaau, and many 

 others, exist in all or nearly all the parts of these membranes. 

 The follicles are round, or obround, graniform, of a variable 

 size and generally very small: they are situated, in part, in 

 the thickness of the membrane, and project more or less under 

 its adhering surface. They have generally the form of a 

 little ampulla, whose mouth more or less lengthened, opens 

 on the free surface of the membrane. They are formed by 

 a reflected fold of this membrane, constituting a depression 

 or a little cul-de-sac. They constitute the pores that are per- 

 ceived on the surface of the skin, in the nose particularly, as 

 well as the granulations that line and elevate the mucous 



* See M. Malpighi, Epistola de structurd glandularum, etc. in op. posthum. 

 Opusculum, anatomicum, de fabrica glandularum, continens, binas episto- 

 las. Boerhaave et F. Ruyschii, etc. in op. omn. Ruyschii. A. Kaau. Per' 

 spiratio dicta ffippocrati, ttc. Cap. xi. xii. et xiii. 



