In the course of the necrotic stage of the disease the laryngeal framework may cave in, and a stenosis be produced which may quickly put an end to the patient's life unless tubage--as explained under the head Oedema--or tracheotomy be performed. A loose piece of dead cartilage getting into the rima can produce the same fatal effect. Smaller or larger pieces of necrosed cartilage, sometimes partially or wholly ossified, have been expectorated, or, post-mortem, found lying in the respiratory passage, looking dirty-yellowish or blackish. Fistulous openings may take place in the larynx, pharynx, and in the skin covering these parts. Gaucher has reported an extraordinary case in which a perichondritic abscess of the thyroid cartilage had opened into the vertebral canal, as well as externally by the side of the sterno-cleido-mastoid muscle. If the perichondritis has followed deep-going ulcerative destruction of the mucous membrane, the perichondritic abscess bursts more easily, and less burrowing of the pus usually takes place. In the rare termination of healing of the necrotic stage of perichondritis the loss of cartilage-substance is supplied by connective-tissue granulation emanating from the perichondrium. Cohen has reported a case in which there was apparently a reproduction of the whole cricoid cartilage, the necrosed original one remaining in the interior of the larynx as a foreign body. Just as laryngeal stenosis is the grave danger during the continuance of the disease before the perichondritic abscess has opened from its protrusion into the laryngeal cavity, together with the accompanying oedema, and from the undermining of soft parts by burrowing pus, and after the abscess has opened from exfoliated pieces of cartilage blocking the interior, or, when eliminated, from caving in of the laryngeal framework, so laryngeal stenosis is the grave consequence of the disease from remaining deformity, cicatricial contraction, ankylosis of the crico-arytenoid articulation, etc. An open perichondritic abscess may also lead to extensive gangrenous destruction, and occasionally to subcutaneous emphysema.