Introduction
The upper respiratory passages are of the utmost importance in the mammalian economy, since the freedom of passage of air through them is a determining factor in all bodily activity. Although only the nose and larynx are cited in the title of this communication, yet it is impossible to refer to them without considering the intervening channels and also the lower respiratory tract; since in man the pharynx is capacious, forming part of the upper air passage and since the mouth of the esophagus is in close relationship to the larynx and is associated with it in the mechanism of swallowing, the present inquiry will extend itself to cover a wide subject.Not only in relation to vital bodily processes, but also in directing activity, the nose and larynx are extremely important; the former has the function of distinguishing between foods and of giving aesthetic pleasure, while the larynx