32 Organs of the Animal Body : their Forms and Uses. 
, Fig. 19. — LuiKj of the Slieep (inferior vieic). 
J 
1. Right lung. I 4. Heart. 
2. Left lung. 1 5. Arteries (carotid). 
3. Windpipe. j 6. Large veiu (veua cava posterior). 
be possible to explore all the tubes (bronchial tubes), because 
they are very numerous, as Fig. 20, showing the divisions of 
only one bronchial tube, will indicate. 
In the course of this examination the farmer will note that the 
tubes, if healthy, are quite empty, and the lining membrane is 
of a pinkish-yellow colour, covered with clear mucus. If any 
foreign bodies, or any parasites, as the thread-worms, which often 
infest these tubes, are present, they will be seen without difficulty. 
To complete the inspection of the organs of breathing, the 
portions of windpipe in the neck must be traced up to the \)a.c\i 
of the mouth, where it ends in the organ of voice (larynx), 
shown in the next figure (21). 
Through the mouth and nostrils there is free communication 
between the larynx and the outer air. The horse, owing to the 
great size of the soft palate which shuts off the mouth, only 
breathes through the nostrils. 
Uses of the Breathing Organs. — Breathing is by most people 
looked upon as the essential vital function ; and it may be 
allowed that it is rather more concerned with the continuance of 
life than other functions are, as proved by the fact that when 
the circulation and brain have ceased to act, the life may be 
saved for a time by keeping up the breathing by artificial 
