ON RESPIRATION. 131 



sucked in air during the action of crib-biting, it 

 must necessarily enter the lungs, as the orifice 

 of the windpipe is always open, except at the 

 moment of deglutition, and air cannot be sucked 

 inwards without a cavity being formed for its 

 reception, as is the case in inspiration. The 

 only way in which air could enter the stomach 

 would be by the action of swallowing; but air 

 could not be swallowed whilst the mouth was 

 open. This disease, therefore, seems to consist 

 in a spasmodic affection of the oesophagus and 

 trachea, excited by some sympathy with the 

 muscles of the jaws. But from whatever cause 

 the habit of crib-biting may arise, it is always 

 deemed incurable. 



It is customary, however, to buckle a strap 

 round the upper part of the neck, in order to 

 prevent the movement of the windpipe. A horse 

 subject to this complaint decreases much in va« 

 lue, as he is generally lean and emaciated, and 

 therefore incapable of performing much labour. 

 KU He 



