In a very large number of the cases of tuberculosis of the Fallopian tubes, the lesions resemble in all respects those of ordinary salpingitis, and are not in any way recognizable by the naked eye as characteristic of tuberculosis. There are no cheesy contents; there are no tubercles upon the peritoneum; the mucous membrane shows no macroscopical changes that would lead to the suspicion of tuberculosis. In these cases the tubes are usually closed at the abdominal ostium; there may or may not be cystic distention; and the adhesions, which are usually very firm, distort the shape of the tube and bind it to the posterior aspect of the broad ligament, the uterus, or other pelvic structure. Until recent years such cases were supposed to be simple cases of salpingitis. Careful microscopic examination, however, has shown that this forms one variety of tubal tuberculosis, and that a certain proportion of such cases of salpingitis are tubercular. The term “unsuspected tuberculosis” has been applied by Williams to such cases. [Illustration: FIG. 153.--Tuberculosis of the Fallopian tubes: _A_, tubercular nodules.] Cases of tuberculosis of the Fallopian tubes may be divided into three classes: Miliary tuberculosis; chronic diffuse tuberculosis (cheesy tubes); and chronic fibroid tuberculosis. _Miliary tuberculosis_ of the tubes may be a part of a general miliary tuberculosis, or it may occur primarily in the tube. Microscopic examination shows giant epithelioid cell-tubercles scattered throughout the mucous membrane. Miliary tuberculosis is the first stage of tuberculosis of the tubes. The process may progress no farther, or it may become converted into one of the other varieties. In _chronic diffuse tuberculosis_ the mucous membrane is infiltrated with epithelioid cells, miliary tubercles, and areas of caseation. The tube may be filled with cheesy material or with pus, and in time the mucous membrane becomes completely destroyed. In this form of tuberculosis the gross appearances are usually characteristic, and are those which have already been described. In _chronic fibroid tuberculosis_ there is a great increase of connective tissue between the tubercles. The lumen of the tube is distorted, and a few miliary tubercles are found scattered through the mucous membrane. This form of the disease is very slow and chronic, and represents a usual method of spontaneous cure. Since the discovery of so-called unsuspected tuberculosis of the Fallopian tubes the disease has been found to be much more frequent than was formerly supposed. Williams found tuberculosis of the tubes in one out of every twelve operations for the removal of tubes and ovaries that were the seat of past or present inflammatory disease. Dr. Beyea and I have found tuberculosis of the tubes present in 18 per cent. of the cases that were subjected to the operation of salpingo-oöphorectomy for inflammatory disease of the tubes.