THE 
VETERINARIAN. 
VOL. XVII, No. 197. MAY 1844. New Series, No. 29. 
CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 
By JAMES Mercer, M.D., Fellow of the Royal College of Sur- 
geons, and Lecturer on Anatomy, 8;c., Edinburgh. 
[Continued from p. 209.] 
V . — On the normal Structure and abnormal Conditions of the 
Larynx in the Horse, and domestic Animals generally. 
UNDER the general head of the organs of respiration are em- 
braced a series of structures, all conducing to the performance of 
the essentially vital process of aeration and purification of the 
blood. It therefore includes the intrinsic aerating organs, the 
lungs, with their inferent tube, the trachea ; and, appended to this 
latter as a subsidary structure, are the series of cartilages and a 
bone constituting the larynx or organ of laryngeal voice. 
Situated, then, as this latter organ is, at the anterior part of the 
air- tube, and forming, as it does, the immediate entrance to the 
lungs, it will follow, that if any change occurs in its normal struc- 
ture, or any derangement happens in its mechanism, an immedi- 
ate effect will be produced on all the phenomena of respiration, 
and, through them, on the organs of circulation and of enervation. 
Indeed, it may be with truth affirmed, that, in a physiological 
point of view, the ultimate bronchial vesicles are of the greater 
importance to respiration and to life in the ultimate ; but in a pa- 
thological point of view the integrity of structure and mechanism 
of the laryngeal apparatus is of a still greater and more urgent 
importance to the proximate and immediate well-being of the 
animal. 
The immediate importance, therefore, of this organ to life, and, 
even when the existence is not actually endangered, to the comfort 
and well-being of the animal, must render any deviation from its 
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