THE OPERA TION FOR ROARING. 



83 



and posteriorly by the cricoid ring. Error may occur here 

 and the space between the cricoid and first tracheal rings be 

 mistaken for the crico-thyroidean ligament. This is readily 

 obviated by careful digital palpation, which reveals the 

 triangular crico-thyroidean ligament with its rounded apex 

 directed forward and its lateral borders sharply defined by 

 the hard borders of the alse of the thyroid cartilage, while 

 the base of the triangle rests upon the more elastic anterior 

 border of the cricoid cartilage. 



Fig. 3. 



Laryngeal dilator in position. 



Having carefully identified the crico-thyroidean ligament, 

 place the back of the scalpel against the anterior border of 

 the cricoid cartilage, accurately upon the median line, the 

 point directed obliquely backwards toward the cavity of the 

 trachea. Push the scalpel through the ligament into the 



