ROARING. 51 



reposing, for ease^ almost the entire weight of his head. The 

 effect of this on the larynx is, that while one side is com- 

 pressed, and cannot act, the other is left, comparatively, at 

 liberty; or, at least, so far unconstrained, that by some extra 

 exertion, the muscles on that side are enabled to perform 

 their functions, while on the former no action can take place 

 at all. 



I had long framed this theory in my mind, when one 

 day perusing Mr. Youatt^s Lectures in the Veterinariariy 

 I was not a little gratified to observe that my friend had 

 been entertaining some such notions as my own, although he 

 had not gone the same length in his explanation. His words 

 are — ^' In the far greater number of cases there is distortion, 

 rendering the muscles on one side useless, and, therefore, 



causing them to waste away The wasting of the 



muscles, therefore, is the ejfect, and not the cause, of that 

 which produces roaring/^ 



Now that fashion bids us to leave our bearing-reins at 

 home — and a very good fashion, when horses have been pro- 

 perly bitted, this is — ^we shall find, probably, some diminu- 

 tion in the number of harness-horses that become roarers. 



The late Mr. J. Field has narrated three cases of the 

 dissection of roarers : — In the first case " the crico-aryte- 

 noideus muscle and two others on the left side were so pallid 

 that he felt quite satisfied of the cause. '^ In the second^ 

 *^ musculus arytenoideus sinister completely wasted. ^^ In the 

 third (a bad roarer), " all the muscles belonging to the left 

 side of the laryngeal cartilages wasted and pallid.'^ 



Query. — Are the muscles on the /^/ side more subject to 

 atrophy than those on the right ? and if so, Why ? 



Deformity of the larynx or windpipe, by which I 

 mean original malformation of them, is included by the French 

 veterinarians among the causes of roaring. I do not 

 remember ever having met with a case of the kind ; though 

 I once saw a preparation which gave me great reason for 

 believing that the canal of the windpipe might be mis-shapen 

 even from birth. 



It was a wet preparation. The tube of the windpipe. 



