SYMPTOMS.--It usually comes on after an injury or as a result of the presence of a mechanical obstruction or irritation, the presence of a bone or pin being frequently invoked as an explanation of the feeling. In a few cases the sensation is suggestive of an alteration of the structure of the parts. Patients are inclined to think that they have a tumor or that there is some deformity. In the first class of cases there is a sense of pricking or of scratching in the larynx. This is not constant in locality or in intensity. There will be times, occasionally days, in which the sensation may be entirely absent, after which it returns with great severity, the patient insisting that the cause of the trouble has simply changed its location--in other words, that there is a migratory body in the throat. That form of paræsthesia in which the sensation is that of a tumor or malformation is also irregular in the mode of its manifestation or kind of disturbance. Like the other forms, it comes and goes, changes its location, and undergoes modification in its character. It may be associated with neuralgia. DIAGNOSIS.--Hyperæsthesia and paræsthesia are recognized by the symptoms already described and by the aid of the laryngoscope. The mirror reveals the fact that the parts are normal in structure and that there is no foreign body present. The mucous membrane may be hyperæmic or anæmic, but is not the seat of any active inflammation. The excessive sensibility and pain of the larynx in ulceration of the parts will be excluded from this group of troubles by the revelation of the laryngeal mirror. Cases of pain or perverted sensation dependent upon the disorders of the nerve-centres usually involve the whole range of functions supplied by the pneumogastrics, and will generally be recognized by this fact. Such cases can hardly be called local, and do not belong to the group of affections embraced in this article. PROGNOSIS.--The prognosis of simple paræsthesia of the larynx is not grave. Though it may exist for a long time, it, so far as we know, does not terminate in death. While it sometimes results in recovery without treatment, it in a large proportion of cases yields only to both local and general treatment. Its duration is uncertain. Paræsthesia coming on after the presence of a foreign body in the organ may last many months and then gradually disappear. This result will be largely aided by the moral support which is gained if we can convince the patient that the sensation is entirely a delusion.