10 ROARING IN HORSES. 



circumscribed by the epiglottis, the aryteno- 

 epiglottic folds, and the arytenoid cartilages, 

 is shrunk up and rendered manifestly 

 unsymmetrical by the abnormal position 

 occupied by the left arytenoid being lower 

 and nearer the middle line than its fellow. 

 The falling of this cartilage necessarily 

 causes a change of position of the vocal 

 cord attached to its lower edge ; it is 

 turned slightly backwards and inwards and 

 therefore towards the opposite vocal cord, 

 producing a very noticeable shortening of 

 the lower part of the glottis (fig. i). These 

 anatomical alterations, more or less marked 

 according to the duration of the affection, 

 are generally in proportion to the respiratory 

 sound noticed during life. Immediately they 

 exist the action of the larynx becomes 

 very imperfect. The posterior and lateral 



