186 GENERAL ANATOMY. 



membrane in many places; the cavity. of these follicles is ex- 

 tremely small in comparison with the thickness of its parietes. 

 They are formed by the whole membrane, whether still pre- 

 serving its thickness, or having it increased or diminished. 

 They are surrounded by an immense number of minute vas- 

 cular ramifications. The majority of these little ampulla are 

 simple, distinct, and placed more or less apart from each other; 

 but in certain parts of the skin, and of the mucus membranes 

 especially, follicles are found variously assembled and com* 

 posed. Besides these follicles of which we are speaking, the 

 tegumentary membranes, and chiefly the internal one, pre- 

 sents many depressions, whose orifice is as large as the bottom, 

 and which are called alveolar, and both the one and the other 

 present a great number of little tapering, or infundibuliform 

 depressions. The follicles differ from each other, also, in the 

 nature of the liquid they secrete and contain : those of the skin 

 are called sebaceous follicles, and those of the internal tegu- 

 ment, mucous follicles, so styled on account of the liquid they 

 furnish; those of the mucous membranes in the vicinity of the 

 skin are almost of a mixed nature, participating of both. 



247. The teguments have a foliated texture; throughout 

 a great part of their extent they are evidently formed of two 

 layers, the dermis and the epidermis ; in many places, another 

 tolerably compound layer is found between the two first ; and 

 in a great number of parts, there are, besides, appendages, or 

 productions, arising from the free surface of the membrane. 



248. The dermis, whatever differences it presents in the 

 two teguments and in their divisions, is always the deepest 

 part of them, the thickest, that which forms their base, and on 

 the surface of which the others are placed. It is formed of a 

 layer of fibrous cellular tissue, more or less dense, furred, and 

 leaving interstices through which pass various other parts. 



249. Blood-vessels, lymphatics and nerves, more or less 

 numerous, are distributed and ramified through the thickness 

 of the dermis and on its supernces, where they form inequali- 

 ties called papillae, villosities, vascular buds, and which will 

 be more exactly defined and described, when speaking of 

 each of the two teguments. 



