Besides, the nature of the mucous epidermis is the same as that of the cutaneous. Submitted to the action of the same agents, it gives the same results. The excrescences formed on its surface are also analogous, though much more rare. It becomes callous by pressure. Chopart relates the case of a shepherd, whose urethra became so, from frequently introducing a small stick to procure pleasure. We know the density that this covering has in the stomach of the gallinaceous animals, and in certain cases in which the mucous membranes come out of the body as in prolapsus of the rectum, the vagina, the womb, &c. Sometimes in those cases the pressure of the clothes produces in this epidermis a thickness evidently greater than what is natural to it; it is this which then makes these membranes lose in part the bright red that characterizes them in the interior. II. _Epidermis of the deep seated mucous surfaces._ The epidermis gradually becomes more delicate, and is soon almost insensible, on the internal mucous membranes. 1st. In the stomach, the intestines, the bladder, the gall-bladder, the vesiculæ seminales, in all the excretories, &c. the most delicate instrument cannot raise it up. 2d. In the maceration and ebullition of the mucous system of these parts, I have never seen the epidermis raised up on its surface. 3d. I have drawn out of the abdomen of a dog a portion of intestine; its mucous coat has been laid bare by an incision, and I have applied an epispastic to it; more redness was seen upon the free surface of this coat, but no pellicle was raised up from it. 4th. We do not see in preternatural anuses, complicated with inversion, excoriations analogous to those of which the surface of the lips, that of the glans, &c. are the seat. 5th. I have already had frequent occasion to open bodies affected with acute or chronic catarrhs of the intestines, the stomach, the bladder, &c.; now I have never seen the epidermis separated by inflammation, as happens after erysipelas, phlegmon, &c. upon the cutaneous organ. 6th. We do not see upon the deep seated mucous surfaces those exfoliations, desquamations, &c. so frequent upon this after many affections.