446 OPERATIONS—TRACHEOTOMY. 
is more general to open the windpipe at a similar distance from the jaw, 
and, assuredly, the superior incision has this advantage, that there is 
less to cut through. But where no important nerves or vessels are en- 
dangered, surgery cares little about the depth of a wound, the chief 
attention being given to the probable after-consequences. 
The superior portion of the neck is especially the seat of motion; it 
varies with every turn and movement of the head. Hence the end of 
the tube is apt to be brought into constant contact with the lining mem- 
brane of the trachea, and horses have been slaughtered with huge 
tracheal abscesses, to all appearance produced solely by wearing the 
tracheotomy tube. 
To avoid this danger the author chooses for incision a spot nearer tu 
the chest, where the motion is less constant and not so varied. Even 
at this last place all danger is not entirely surmounted, in consequence 
of which a horse, while wearing a tracheotomy tube, should never be 
permitted to feed from the ground. 
DIAGRAM, SHOWING THE STRUCTURES TO BE THE MANNER IN WHICH THE CARTILAGES 
INTERFERED WITH DURING THE PERFORM- OF THE TRACHEA ARE TO BE EXCISED. 
ANCE OF TRACHEOTOMY. 
1.1. The sterno-maxillares muscles—a pair—have to be separated, being joined by fine cellular tissue. 
etna sterno-thyro-hyoidei muscles, lying under the first pair, also have to be divided, being similarly 
38. The trachea, which is fully exposed when the above muscles are disunited. 
At the commencement, when the operator has leisure, he generally 
does not cut too deep. The first incision fairly divides the skin and 
panniculus carnosus quite in the middle of the neck, and is rather louger 
than a by-stander would deem to be absolutely necessary. The elasticity 
of the skin will somewhat shorten the opening, while the torture of 
