This is the name of a symptom rather than a disease. It implies a sound made in breathing in connection with some contraction of the air passages. The term is however usually reserved for those conditions in which the sound results, from chronic disease or malformation, the noise attendant on laryngitis and other acute diseases being rarely spoken of as _roaring_. In neither case does the noise indicate more than that there is some impediment to the ingress and egress of air through larynx or trachea. The pitch of the note varies exceedingly with the causes that produce it and with the hurried nature of the breathing. There have thus arisen the epithets of _grunter_, _roarer_, _whistler_, _highblower_, _piper_, _trumpeter_, _wheezer_, _etc_. The most common distinctions are those of _roaring_ and _whistling_. The _roarer_ produces a loud deep basso sound in inspiration, the larynx or windpipe being only slightly narrowed while the _whistler_ or _piper_ produces a shrill blowing or sibilant noise because of the greater constriction of the passage. The term _grunter_ is derived from the facts that a _roarer_ usually makes a grunting noise when struck or threatened with a cane, and that when the upper cartilages of the windpipe are pinched between the finger and the thumb the resulting cough is prolonged and somewhat like a _grunt_. A _wheezer_ is usually suffering from spasmodic contraction of the bronchial tubes, from broken wind or from chronic bronchitis. A _highblower_ should never be spoken of in the same connection, as the noise is made from a playful flapping of the false nostrils or soft palate and disappears when the animal is put to the top of his speed. It is from confounding _high-blowing_ with _roaring_ that _Eclipse_ and other brilliant performers on the English turf have been erroneously pronounced _roarers_. The noise produced by the _roarer_ is not heard while he stands quiet, nor many cases even during a short trot or gallop. Such horses are in consequence often sold at the hammer and the purchaser is grievously disappointed to find that what he thought a sound horse is absolutely useless for the purpose for which he designed it. =Causes.= Before noticing the symptoms of roaring a consideration of the causes will be useful to enable the reader the better to understand the signs by which the different forms are manifested.