DISEASES OF THE RESPIRATORY ORGANS. 119 
the danger; hence double pneumonia is more fatal than pneumonia 
of one lung. 
THE WINDPIPE. 
The windpipe, or trachea as it is technically called, is the flexible 
tube that extends from the larynx, which it succeeds at the throat, 
to above the base of the heart in the chest, where it terminates by 
dividing into the right and left bronchi—the tubes going to the right 
and left lung, respectively. The windpipe is composed of about fifty 
incomplete rings of cartilage united by ligaments. A muscular layer 
is situated on the superior surface of the rings. Internally the tube 
is lined with a continuation of the mucous membrane that lines the 
entire respiratory tract, which here has very little sensibility in 
contrast to that lining the larynx, which is endowed with exquisite 
sensitiveness. 
The windpipe is not subject to any special disease, but is more or 
less affected during laryngitis (sore throat), influenza, bronchitis, 
etc., and requires no special treatment. The membrane may be left 
in a thickened condition after these attacks. One or more of the 
rings may be accidentally fractured, or the tube may be distorted or 
malformed as the result of violent injury. After the operation of 
tracheotomy it is not uncommon to find a tumor or malformation as 
a result, or sequel, of the operation. In passing over this section 
attention is merely called to these defects, as they require no particu- 
lar attention in the way of treatment. It may be stated, however, 
that any one of the before-mentioned conditions may constitute one 
of the causes of noisy respiration described as “ thick wind.” 
GUTTURAL POUCHES. 
These two sacs are situated above the throat, and communicate 
with the pharynx, as well as with the cavity of the tympanum of 
the ear. They are peculiar to solipeds. Normally, they contain air. 
Their function is unknown. 
One or both guttural pouches may contain pus. The symptoms are 
as follows: Swelling’ on the side below the ear and an intermittent 
discharge of matter from one or both nostrils, especially when the 
head is depressed. 
The swelling is soft, and, if pressed upon, matter will escape from 
the nose if the, head is depressed. As before mentioned, these 
pouches communicate with the pharynx, and through this small 
opening matter may escape. A recovery is probable if the animal is 
turned out to graze, or if he is fed from the ground, as the dependent 
position of the head favors the escape of matter from the pouches. 
In addition to this, give the tonics recommended for nasal gleet. If 
this treatment fails, an operation must be performed, which should 
not be attempted by any one unacquainted with the anatomy of the 
part. 
