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).

In passing down the trachea the following two rules must be kept in
mind:
1. Before attempting to enter either main bronchus the carina must
be identified.
2. Before entering either main bronchus the orifices of both should
be identified and inspected.
_The carina_ is identified as a sharp vertical spur (recumbent
patient) at the distal end of the t