558 NERVOUS DISEASES. 



The following ai'e proofs that air-swallowing and not eructation 

 (belching) is the essential act of cribbing and windsucking : — 



1. The attitude of drawing in the chin and rounding the neck, 

 in which this vice is practised, is that of swallowing and not of 

 belching, in which the head and neck are extended as much as 

 possible. 



2. If the gullet of the cribber or windsucker be laid- bare, observe 

 that during the practice of the vice, a gulp of air passes down the 

 gullet in the direction of the stomach. 



3. Owing to the peculiar construction of the horse's stomach, 

 which, under ordinary circumstances, does not permit of vomiting, 

 in the dead animal, the stomach may be filled with air from the 

 bowel end, without any of the air escaping into the gullet. 



4. The gas in the stomach and first part of the intestines of 

 wind-suckers, has been proved by chemical analysis to consist 

 exclusively of ordinary air. 



5. If this vice were characterised by belching, efforts to prevent 

 its practice would naturally be followed by flatulent distension of 

 the abdomen, which, however, does not ensue if such preventive 

 means be used. 



6. Division of certain swallowing muscles (sterno-hyoideus, sub- 

 scapulo-hynideus, and sterno-maxiUaris) will stop the vice for the 

 time being. 



To me, a thoroughly satisfying proof that swallowing air and 

 not its eructation is the essential act of this vice, is the fact that 

 placing in the animal's mouth a bridle with a hollow mouthpiece 

 perforated with holes (p. 560), will prevent its practice. It can 

 be easily seen that the use of this contrivance, by furnishing, at 

 each side, a way of escape for the air, will render it impossible for 

 the horse to force backwards the air in his mouth ; and that it 

 can in no way check eructation. 



The swallowing of air in cribbing or windsucking appears to 

 serve no useful end ; for its prevention doee not injure the health 

 in any way. 



FREQUENCY OF THE ACT AND MODIFYING CIRCUM- 

 STANCES. — The frequency of the practice of this vice varies 

 greatly in different cases. Animals may be seen engaged at it 

 during and after feeding. Some practise it at each mouthful.. 

 Others begin only after having had their food. The nature of 

 the food and the process of digestion have no influence on its 

 frequency. The affected animal loves to indulge in this vice in 

 solitude, and will often refrain from it, if any person, and, some- 

 "times, if another horse be present. It has been recorded that a 

 cribber refrained from cribbing during the entire duration of the 



