_Examination of the Trachea and Bronchi_.--All bronchial orifices must be identified _seriatim_; because this is the only way by which the bronchoscopist can know what part of the tree he is examining. Appearances alone are not enough. It is the order in which they are exposed that enables the inexperienced operator to know the orifices. After the removal of the laryngoscope, the bronchoscope is to be held by the left hand like a billiard cue, the terminal phalanges of the left middle and ring fingers hooking over the upper teeth, while the thumb and index finger hold the bronchoscope, clamping it to the teeth tightly or loosely as required (Fig. 63). Thus the tube may be anchored in any position, or at any depth, and the right hand which was directing the tube may be used for the manipulation of instruments. The grasp of the bronchoscope in the right hand should be similar to that of holding a pen, that is, the thumb, first, and second fingers, encircle the shaft of the tube. The bronchoscope should never be held by the handle (Fig. 64) for this grasp does not allow of tactile sense transmission, is rigid, awkward, and renders rotation of the tube a wrist motion instead of but a gentle finger action. Any secretion in the trachea is to be removed by sponge pumping before the bronchoscope is advanced. The inspection of the walls of the trachea is accomplished by weaving from side to side and, if necessary, up and down; the head being deflected as required during the search of the passages, so that the larynx be not made the fulcrum in the lever-like action. [FIG. 64.--At A is shown an incorrect manner of holding the bronchoscope. The grasp is too rigid and the position of the hand is awkward. B, Correct manner, the collar being held lightly between the finger and the thumb The thumb must not occlude the tube mouth.] _The Fulcrum of the Bronchoscopic Lever is at the Upper Thoracic Aperture; Never at the Larynx_.--Disregard of this rule will cause subglottic edema and will limit the lateral motion of the tip of the bronchoscope. It is the function of the assistant to make the head and neck follow the direction of the proximal end of the bronchoscope and thus avoid any pressure on the larynx (see Peroral Endoscopy, Fig. 135, p. 164).