EOAEINe. 281 



pressure upon the trunk of the nerve or from dividing it, 

 will produce paralysis of the laryngeal muscles, and passive 

 closure of the glottis, and roaring as a consequence of the 

 latter ; so that here we have examples of states of the larynx 

 of a nature the very opposite to each other, producing effects 

 precisely similar. 



V. — Stricture of one or both nasal passages. Mr. James 

 Turner, an eminent veterinary surgeon, relates a very instruc- 

 tive case of this kind m the Veterinarian for 1849, pp. 14 

 and 15. 



VI. — ThicTcening of tlie mucous mentbrane of the larynx 

 is sometimes a cause of Eoaring ; more frequently, however, 

 it causes a roughness, or wheezing in the breathing. 



VII. — Curvature and ossification of the urindpipe arising 

 from tightly reining v/p the head. This is not a common 

 cause, especially now that bearing reins have gone so much 

 out of use. 



VIII. — Ulceration of the mucous membrane and other 

 tissues of the larynx. This is not a common cause. Atrophy 

 of the muscles of one half of the larynx is perhaps of all 

 other causes the most common. 



AiTECTiONS ALLIED TO EoAEiNG.— There are other affec- 

 tions of a nature closely allied to Eoaring, these are — Wheezing, 

 Piping or "Whistling, Grunting, and High Blowing. 



Wheezing is a peculiar roughness accompanying the breath- 

 ing in numbers of horses which have previously suffered from 

 an inflammatory affection of the larynx. It is rarely heard, 



