ABSTRACT
The chief of the organs used in the production of speech is the larynx, and it remains to consider the important matter of the physiological relation between the use of the larynx and the forceful use of the arms. Though crucial in the production of speech, the larynx did not evolve for the purposes of speech. The larynx has now been well studied, and particularly in the classic work of Sir Victor Negus, The Mechanism of the Larynx. The larynx first appeared in the animal kingdom when the lung evolved, making it possible to breathe air. The larynx then evolved, at the upper end of the pulmonary air tract, for this purpose of excluding all but air and protecting the passage for respiration. But in the more advanced of the animals in rats, dogs, bears, monkeys, anthropoid apes and man the larynx evolves further as an inlet valve, which prevents the entry, at first of water, and then of air.
