THE VOICE. 231 



9. The interval or space between the true cords of the 

 voice is constantly varying, not only when their vocal 

 function is in exercise, but also during the act of respira- 

 tion. Every time the lungs are inflated, the space 

 increases to make wide the entrance for the air; and dimin- 

 ishes slightly during expiration. So that these little cords 

 move gently to and fro in rhythm with the expansion and 

 contraction of the chest in breathing. These movements 

 and others may be seen to take place, if a small mirror 

 attached to a long handle be placed back into the upper 

 part of the throat; the handle near the mirror must be 



FIG. 56. 

 A VIEW or THE VOCAL CORDS BY MEANS op THE LARYNGOSCOPE. 



bent at an angle of 45, so that we may look "around the 

 corner," so to speak, behind the tongue. The position 

 which the mirror must assume will be understood by 

 reference to Fig. 38. A view of what may be seen under 

 favorable circumstances, during tranquil inspiration is 

 represented in Fig. 56. The vocal cords are there shown as 

 narrow, white bands, on each side of the central opening, 

 and since the image is inverted, the epiglottis appears up- 

 permost. The rings partly seen through the opening be- 

 long to the trachea. This little mirror is the essential part 



9. Variation in the interval between the true cords of the voice? Experiment 

 with the mirror ? 



