In examining the membrana tympani special attention should also be paid to its superior border, to examine the condition of the thin portion above the short process (the membrana flaccida) and of the superior wall of the meatus. Both these parts seem very liable to morbid conditions. The membrane at this part may be densely thickened, or may seem wanting altogether, and the neck of the malleus, which lies behind it, seem quite exposed, or at other times a minute perforation may be seen there, or even a red mass of granulations; and very often, especially in conditions connected with longstanding discharge or accumulation of epidermis in the meatus, the upper wall of the meatus at the superior and inner part seems largely excavated, and masses of thickened discharge or epidermic flakes may collect, sometimes to an immense extent, and give rise not only to great local irritation but to general distress. This is quite independent of the formation of the sebaceous tumours, consisting of dense layers of epidermic cells, which sometimes form in the meatus, and are also very apt to partially destroy its superior wall.

Thicker and thinner portions of the membrane are easily distinguished, thinner portions being dark, as less reflecting; they are also more concave. They are often to be seen as dark spots on a generally thick and white membrane, when they may be assumed to be for the most part scars; but most frequently thinned and sunk-in portions of the membrane are to be seen in the upper and

D

posterior parts, about in the position of the head of the stapes; and they are often in contact with or even adherent to that bone. The cause of the thinning of the membrane in this position is a matter needing to be further explored, but it is almost certain that, in the majority of cases, it is due to the pressure exerted by masses of dense secretion formed during catarrhal affections of the tympanum, and which tend to collect especially in that region; that is, to cling around the ossicula, and very probably to accumulate in the posterior "pocket" of the membrane. I have certainly seen more "bulgings" of the membrane from collections of mucus in this part than in any other, and it seems to me that it is due to its entanglement in that position, owing to the presence of the chain of ossicles; and we cannot but feel how probable it is that mucus that had collected in this position, becoming dense and dry, should give rise to increasing deafness after all appearances connected with increased secretion had passed away. To what extent this is the case is one of the problems on the solution of which the prognosis in a large class of cases depends. For a "rigidity" due to that cause would be evidently much more susceptible of remedy than if it were the result of thickening or hardening of the structure of the mucous membrane itself, or of ligamentous or other immobility of the joints of the ossicula. My experience has led me to believe that the presence of such driedup mucous secretion investing the chain of bones

is one of the most frequent conditions which determine deafness in the large mass of chronic cases which occur, with more or less clear history of protracted or recurring attacks of catarrh dating from long before.

In connection with the presence of abnormal secretions in the tympanum, other appearances are to be regarded. The slightest of these is one that may occasionally be seen in the early stages of catarrh, especially in the young-the outline of distinct bubbles on the inner surface of the membrane. It is necessary for this that the membrane should not have lost its transparency, and that the tube should permit the passage of air; the appearance will sometimes follow inflation of the tympanum by the india-rubber bag, and the air may be heard to enter with a slight moist sound. A more advanced stage of excessive secretion will give rise sometimes to a mottled or cloudy whiteness of the membrane, varying in degree at different parts, and which may be seen to be due, not to opacity of its external surface, but to a whitish semi-fluid substance in contact with it internally. Appearances of this kind lend great countenance to Dr. Jago's opinion that the drying up of mucus into a thin layer on the internal surface of the membrane is a cause of deafness, which may sometimes disappear with a sudden crack, due to the peeling off of the secretion.

Another appearance presented by secretion within the

tympanum is that of a slight yellowish discoloration. situated at the most dependent part, and with a curved superior border, which gradually shifts its position with the movements of the patient's head, thus showing that it is due to the presence of a fluid. I believe it has not been noticed that the hearing varies in accordance with these changes in the position of the fluid, in cases that have been observed; but the changes in the power of hearing in accordance with the position in which the head is held are frequently very striking, and a shifting of more or less fluid secretion always suggests itself as a possible cause, but not yet with sufficient proof. The secretion in these cases, of course, is perfectly fluid, generally serous; but the existence of even a large amount of merely serous fluid is no evidence that a more viscid secretion is not also present.

Another appearance of excessive secretion is an obscure, yellowish, greenish-yellow, or brownish tint, appearing through the posterior part of the membrane, which is almost always very concave, and the tube more or less obstructed. In these cases the appearance does not change with movement of the head, and the secretion is of dense and viscid character. On inflation of the tympanum a distinct yellow bulging is formed, unless the membrane is firmly held down by adhesions to the inner wall of the tympanum, but even then powerful inflation will often produce a limited protrusion of the discoloured part. In not a few cases, however, according

to my experience, inspissated secretions may be present in the tympanum, and to a large extent, so as seriously to interfere with the hearing, without any appearance characteristic of their presence, the membrane being at the most white and opaque, and perhaps flattened. In some of such cases I have found the history-being that of a distinct catarrh, as, for example, an attack of cold following a fall into water-a true guide to the presence of inspissated mucus.

Alike in cases in which excess of secretion is present and when it is not, the membrane may sometimes be seen fallen in upon the promontory and more or less adherent to it, or bound by bands of adhesion to various parts of the tympanic wall or the ossicula. In the former case the appearance at once reveals the condition, which was termed by Wilde collapse: the membrane is very much thinned; it lies evidently too remote from the eye, and the outline of the promontory is more or less distinctly visible; often the niche in which the fenestra rotunda lies is clearly marked; the malleus is seen to run inwards and to rest upon the tympanic wall, or it may be partly wanting, and most frequently the head of the stapes may be seen distinctly projecting just beneath the upper border of the membrane at its posterior part. Generally the Eustachian tube is obstructed, but if it is pervious, or can be made so, portions of the membrane may be blown out into a more or less bladder-like form, leaving the central part still attached to the projecting