THE ROARING OPERATION 



57 



the thyroid cartilage and extending downward and back- 

 ward to the region of the first tracheal ring. Separate the 

 sterno-thyro-hyoideus muscle on the median line with the 

 scalpel blade or handle as preferred. Control the hem- 

 orrhage. If the operation is performed upon the standing 

 animal with the aid of cocaine and adrenalin, the incision 

 is virtually bloodless. 



Locate the crico-thyroidean ligament, triangular in form, 

 bounded anteriorly and on both sides by the thyroid carti. 

 age and posteriorly by the cricroid ring. Error may occur 

 here and the space between the cricoid and first tracheal 

 ring be mistaken for the crico-thyroidean ligament. This 

 is readily obviated by careful digital palpation, which re- 



Fig. 18. 



Laryngeal dilator. 



Fig. 19. 



Ventricular burr of soft rubber, 

 the sphere on the left having 

 been covered with a thin lay- 

 er of cotton. 



