[Phylogenesis of the human larynx]

The evolution of the larynx from its first appearance in lung fish up to the stage of its more elaborate structure in mammals is reviewed. Each step of development is illustrated by examples from animals. The function of the larynx has been described since the beginning of its evolution as that of preventing the entrance into the pulmonary air tract of any substances except air. In addition to this primitive and all-important function, in the course of the time the larynx, having the physical properties of an organ-pipe, has acquired the secondary function of sound production as an important means of communication.