THE SENSE ORGANS 177 



forehead. Slightly warm the laryngeal mirror, and pass it into the 

 subject's mouth, carrying the mirror horizontally backward until its 

 back touches the base of the uvula. Avoid pressure upon the uvula 

 or contact with the other soft parts. Concentrate the light upon the 

 mirror, and tilt the latter until a view is obtained of the interior of the 

 larynx, remembering that the parts are seen inverted in the mirror. 



Identify the dorsum of the tongue, the slightly yellowish epiglottis 

 with its "cushion," and the glosso-epiglottidean folds of mucous mem- 

 brane. Identify the white and shining "true" vocal cords, the pink or 

 red "false" vocal cords, the aryepiglottidean folds, and the mucous 

 membrane covering the arytenoid cartilages and cartilages of Santorini. 



Observe the differences in the form of the glottis: 



1. During quiet and forced respiration, 



2. While the subject sings a low and a high note, and 



3. While the subject sings the vowel sounds: A, E, I, O, U. 

 12 



