FOREIGN BODIES IN THE TRACHEA. 447 



thrust a cork cylinder, bound round with tow, into the trachea, and 

 fixed it with tape. In ten days the cylinder was replaced by a tube, 

 the latter was removed after six weeks, the trachea being then so far 

 dilated as to admit of easy respiration without a cannula. Sticker 

 dilated the trachea and larynx by means of a metallic spiral, which 

 was left permanently in position. 



(4.) FOREIGN BODIES, TUMOURS, AND PARASITES 

 IN THE TRACHEA. 



Foreign bodies seldom enter the trachea during life. Owing 

 to the sensibility of the mucous membrane of the glottis, they imme- 

 diately produce coughing, and are ejected. Masses of food have 

 nevertheless been repeatedly found in the trachea both in oxen and 

 horses. Tumours of the pharynx, which are common in cattle, 

 sometimes interfere with swallowing, and favour the entrance of 

 food into the trachea. In horses fluid medicines unskilfully adminis- 

 tered occasionally pass into the trachea and bronchi. Dust enters 

 with the inspired air, and may produce pneumonia, especially in 

 horses. Abscesses in the walls of the pharynx or trachea, perforating 

 the mucous membrane, may pour their contents into the air passage 

 and produce fatal pneumonia. Rost saw a cow die thus from 

 suffocation. In animals suffering from tetanus, saliva and medicine 

 not infrequently find their way into the respiratory passages, and 

 produce bronchial irritation. Blood derived from wounds or 

 operations in the mouth, larynx, trachea, or neck may enter the 

 air passage and clot there, producing coughing and occasionally 

 suffocation. Badly-made tracheotomy tubes sometimes break, and- 

 a portion falls into the trachea. This may happen with cannulas, 

 in which the tube is not firmly fitted to the shield. Henderson 

 reports such a case. During tracheotomy, if care is not taken, the 

 disc of cartilage may be drawn into the trachea ; it is carried up and 

 down by the air stream, coughing follows and the disc is expelled 

 through the operation wound. Other foreign bodies rarely enter 

 the trachea, though a case is reported where a horse died in conse- 

 quence of a stem of Robinia pseudacacia 12 inches long passing into 

 the right bronchus, and producing pleuro-pneumonia with hydro- 

 thorax. 



Tracheal tumours are rare, though they have been seen — 

 principally in oxen. They are usually pedunculated, probably in 

 consequence of being continually moved by the air stream. Gurlt, 

 Gerlach, Hink, and others found tracheal polypi in oxen, Rieck and 



