DIAGNOSIS.--With the laryngoscope, the spatula, and the finger the seat, the degree, and often the nature of the infiltration can be determined. A successful laryngoscopical examination may sometimes require in such cases more than ordinary skill, and there is often so much tumefaction that the parts are not easily recognizable. The epiglottis may appear as a thick roundish tumor, or be of a more or less indistinct horse-shoe shape, overhanging the laryngeal aperture; the ary-epiglottic folds may be converted into large lateral cushions pressing against the arytenoid bodies, or be merged with the latter into huge, irregularly pear-shaped, oval, or globular masses; and the ventricular folds may be immensely tumefied, or else, by means of the swelling and the being pushed into a horizontal position of the whole lateral lining of the upper laryngeal cavity, may be obliterated altogether. Glottic oedema never occurs except with supraglottic, and the upper surface of the vocal bands may look elevated, arched, and bladder-like, even if only the thyro-arytenoid muscles are infiltrated. In infraglottic oedema there is usually neither epiglottic nor supraglottic oedema; pads are seen underneath the vocal bands, either ring-shaped or projecting from side to side toward the middle line, and fill up to a greater or less degree the rima glottidis. The oedematous parts have sometimes a pinkish, but usually a yellowish, translucent or semi-translucent aspect. Accumulation of pus lessens the translucency and sometimes makes the yellow more marked. Sanguineous {116} infiltration shows a bluish-red or livid discoloration. In chronic oedema the color is lighter, sometimes a dirty gray. I have already explained the proper method of using the spatula. It reveals in all cases, sometimes best during retching, the epiglottis, and in many cases the ary-epiglottic folds. With the finger these parts can be touched, and all the more easily when they are swollen; but great care must be exercised to avoid provoking by digital examination a suffocative paroxysm. When felt by the finger the peculiar elasticity or fluctuation present is unmistakable. PROGNOSIS.--Laryngeal oedema is always a very dangerous condition--in a chronic case less so than in an acute one. The prognosis depends largely upon the causative or accompanying disease. The more local the oedema and the more promptly medical, and in most instances surgical, aid can be had, the more favorable is the prognosis, though uncertain even then. Sometimes a rapidly fatal attack supervenes in a mild, chronic, or apparently convalescing case. In abscess formation it is generally favorable unless the underlying disease makes it the reverse.