translated into motion; this motion is probably reflex, but not necessarily through the centres, such as the brain or cord. The motion is of the subjacent muscles. Second, the mechanical irritation produced by the presence of a drop of water or a morsel of food in the larynx results in violent and explosive cough. The cough persists until the offending drop or body has been removed. This kind of sensibility calls into action distant muscles. There is no spasm of the adductors of the glottis, as in the case of the application of caustics. It is probable that the filaments of the nerves, the irritation of which gives rise to spasm, are distributed more generally than those which preside over reflex action at a distance and produce cough. The one set of functions are designed probably to protect the organ from the intrusion of foreign bodies; the other for their expulsion, as well as for the removal of the secretions of the parts or of matter brought up from below. The hypothesis of a third form of sensibility, as described by Elsberg--namely, the dolorous--seems hardly to be demanded for the larynx more than for all other mucous surfaces subject to pain. The nerve-cells of Rossbach in the mucous membrane may be peculiar to the larynx and trachea, as he claims, but further observations are required for the demonstration of this as a special histological fact distinguishing laryngeal from other mucous surfaces. [Footnote 1: _Dic. Eng. des Sci. med._] [Footnote 2: _Int. Med. Cong._, 1881.] [Footnote 3: _Ibid._] PERVERSION OF SENSATION OF THE LARYNX. There is some difficulty in grouping the derangements of the sensibility of the larynx, for the reason that in many cases the perversion of this function is only a symptom of some other disease of the organ. Probably in all cases the trouble is, in fact, an expression either of disturbance in the structures of the larynx, involving more than the sensory nerves, or it is the result of change in structure or function of neighboring or distant parts. Various attempts have been made to classify these disorders according to the kind of perversion and also according to the cause of the trouble. Elsberg, in a paper presented to the International Congress, London, 1881, p. 224. vol. iii., makes an attempt at a scientific classification based upon anatomico-physiological facts. That there is yet much to learn in regard to these facts, especially the physiological facts, will be admitted by every one at all familiar with the literature of the subject. Elsberg, under the term of dysæsthesia, makes two principal divisions--namely, first, disorders having reference to the quantity or intensity of the sensation; this embraces simple hyperæsthesia and simple anæsthesia. The second grand division relates to the quality of the sensation, and includes only paræsthesia or sensory delusions. These grand divisions are still further subdivided.