(Showing the vocal cords.) A, epiglottis; B, section of hyoid bone; C, superior vocal cord; D, ventricle of the larynx; E, inferior vocal cord; F, section of the thyroid cartilage; H, section of anterior portion of the cricoid cartilage; K, trachea; L, section of the posterior portion of the cricoid cartilage; M, arytenoid cartilage; N, section of the arytenoid muscle.

It is also supplied with lungs, and two auricles and two ventricles to the heart; all of which bring it still closer into an alliance with the quadrupedal species of the animal kingdom.

The openings from the ventricles into these vessels are guarded by the semilunar valves.

Tie variously colored yarns to the vessels, so that they may be distinguished when separated from the surrounding parts. Having separated the heart from the lungs, cut out a portion of the wall of the right ventricle towards its lower part, so as to lay the cavity open.