Mucous membranes are very subject to cancerous affections; some are more frequently diseased than others, and especially the mucous lining of the whole alimentary tube. It would, however, be erroneous to regard every such affection as a primary affection of the mucous membrane; for in the majority of cases, the cancer originates in the subjacent cellular tissue and the mucous membrane is diseased secondarily and by contiguity.

Although any of the various cancerous growths may occur in mucous and submucous tissues, yet, so far as I am aware, nothing definite, nothing supported by numerous observations, can be brought forward to prove the occurrence of cancer primarily in mucous membrane, or to show the condition of that membrane, when the cancerous growth appears originally in the submucous tissue, except in the cases of areolar, medullary, and fibrous cancers.

The areolar and the medullary are the forms of cancer in which primary cancerous degeneration occurs in the tissue of the mucous membrane. They are rather frequent.

The areolar is known by its characteristic degeneration: it extends for the most part, over large tracts of mucous membrane, especially in the stomach and intestinal canal.

The medullary presents itself, a. Sometimes as nodules, which are of a round, or slightly convex form, or which even produce a navel-like depression on the free surface of the mucous membrane; they are situated in its parenchyma, but project more or less above its free surface: and they have a lardaceous, or medullary (encephaloid) appearance. Cancer of the mucous membrane in this form is scarcely ever the primary cancer in the system, but is almost always a consecutive affection, combined with some previous cancerous disease of the adjoining submucous tissues.

B. Another Form Of Cancer Which Occurs More Frequently

Another Form Of Cancer Which Occurs More Frequently, and particularly on certain mucous membranes, is looked upon most properly as a kind of medullary cancer. When in an advanced state, it forms more or less extensive spherical tumors (fungi), which are attached by a constricted neck-like base, or even what might, with reference to their bulk, be named a pedicle. They take root in the parenchyma of the mucous membrane and the immediately adjoining cellular tissue. They are for the most part loose, very vascular, abundantly supplied with blood, and of a bluish-red color; and they readily swell, and bleed frequently and severely. They are composed of a delicate membranous texture, that sometimes breaks down into fibres, sometimes into laminae, and is filled with a whitish or whitish-red marrow, or a similar encephaloid juice. In many cases, the mucous membrane is affected in this manner at some one circumscribed spot; in other cases the growths spring up on a membrane in the form of smaller excrescences which are attached by a pedicle, and at their free extremities are shreddy and grow like a cauliflower, and are clustered so closely together, that the whole tract of membrane which they occupy seems to be degenerated into them. Their elementary texture, and their development from their mother soil, has been already described, and a special form has been mentioned as an epithelial fungus. I have also shown their alliance with the cauliflower excrescences that occur on anomalous serous membranes, i. e. on the inner surface of cys-toid growths; and, lastly, have mentioned, that they no doubt constitute for the most part the erectile cancerous tumors, as they have been called, particularly by French observers.

They are often found in the mucous membrane of the stomach and intestinal canal; but they are particularly frequent within the urinary bladder. Frequently, and indeed generally, they constitute the primary cancer, that is to say, that which first appears in the organism; and they continue the only one, until by their sanious discharge and hemorrhage, they prove fatal.

Mucous membrane is always affected by fibrous cancer secondarily, being destroyed by the advance of that growth from the submucous tissues. The mucous membrane may be in various conditions: of these some have been described already, and others will be mentioned in the account of the particular organs in which they occur; but there is one character which may be spoken of in this place, which it shares with other structures that become involved by contiguity in cancerous diseases, and more particularly with the skin, namely, that when encroached upon by a mass of cancer, mucous membrane becomes adherent to it, united with it, and at length entirely lost in it.