TUMOUR WITHIN THE WINDPIPE OF A HORSE. 395 
longing life that remained to be done was to perform the opera ¬ 
tion of tracheotomy; but as the ultimate recovery and value 
of the animal^ even when this operation had been performed, 
was very doubtful, we recommended the owner to have him 
destroyed. He was soon after shot, and the same day I 
removed the trachea, which I forwarded for your inspection. 
The case, I think you will agree with me, presents some 
features of interest, not the least being the somewhat rare 
occurrence of obstructions existing midway in the tracheal 
tube, sufficient to cause death. It also shows the importance 
of carefully examining the course of the trachea in cases of 
roaring, as it clearly shows that this affection does not always 
proceed from obstruction to the natural function of respira¬ 
tion in the larynx. The nature of the obstruction and its 
probable cause I must leave for you to explain. 
Believe me, &c. 
To Professor Yaenell. 
REMARKS BY PROEESSOR VARNELL. 
Defective breathing in the horse, accompanied with un¬ 
natural respiratory sounds, being so very common, and the 
special causes which produce it being so various, as well as 
the length of time which in many instances it may have 
existed, beside the uncertainty whether a cure can be effected 
or not, make it important that the pathology of the affec¬ 
tion should be, as far as possible, well understood. It is on 
this account that we have to thank Mr. Watson for a very 
interesting, as well as unusual specimen of disease of the 
trachea, which evidently had been the cause, in the case in 
question, of the defect termed roaring. In this instance the 
abnormal sound was for a time supposed to depend upon 
disease of the larynx, the most common seat of roaring; and 
it was not until the 13th of April, thirty-three days after the 
horse was purchased, that the locality in which the impedi¬ 
ment existed was discovered. In a pathological point of view, 
it is very important that the true history of such cases should 
be known, for this information, especially when conjoined with 
a careful examination of the morbid parts, cannot fail to mate- 
- rially assist us in arriving at definite conclusions as to the cause 
which primarily produced the impediment to respiration. 
Before giving an opinion as to the cause and duration of the 
disease, I will briefly describe the physical appearance of the 
tumour, and also as much as I was enabled to make out of its 
structure. About twelve inches below the cricoid cartilage 
