444 
CONSIDERATIONS ON CRIB-BITING. 
biting with eructation,* supplies the reason of the difference of 
opinion we have adverted to, and is quite conformable to 
what one daily observes. M. Gurlt asserts that the crib- 
biter swallows air, which he the same instant rejects; but 
that, nevertheless, in particular cases, a portion of the air 
having descended into the oesophagus does not reascend into 
the pharynx, but penetrates into the stomach, into wdiich it 
is forced by the contraction of the wall of the oesophagus. 
M. Straut, who has written an admirable memoirf* on crib- 
biting in horses, admits of the view of the matter taken by 
Gurlt, which he explains in this way : — The animal, when he 
incurvates his head upon his breast, does so to gain a point 
cVappui , in order to force a certain quantity of atmospheric air 
into the pharynx, and thus overcome, in this act, the natural 
impediments offered by the velum palati and fauces : the larynx 
is elevated, while coincident muscular contraction draws up 
the fauces to receive the swallowed air. At this moment the 
horse relaxes in his effort, (crib-biters in the air effect the 
movement in slight elevation of the head,) and then the air 
swallowed flows back, and escapes with the characteristic 
sound. With old crib-biters we may convince ourselves by 
auscultation, that the sound attendant on the act is in truth 
produced at the moment of the evacuation of the air ; and 
w r ith horses in whom the air reaches the stomach, a second faint 
supplementary sound may be heard along the oesophagus, 
coming from the air entering the stomachal cavity. This last 
sound has some analogy to the borborygmi (rumblings) of 
the bowels. 
In this manner we may explain very readily how it happens 
that some crib-biters blow their bellies out very much in the 
act, while in others nothing of the kind happens ; so that in 
some horses the vice really proves prejudicial, w T hile others 
seem hardly at all decreased in real worth by it. 
Hurtrel d’Arboral, and numerous Veterinary authors with 
him, have sought the cause of crib-biting in the digestive 
organs : but, in perusing this author’s article on the subject, 
it is easy to perceive that he has collected exceptions to esta- 
blish a general rule, and has mistaken the effect for the cause. 
Indeed, the medical opinions of this writer savour too much 
of the gastro-intestinal organs being the seat of diseases 
obscure in their nature. 
I know many crib-biting horses, but I am not acquainted 
w : ith one instance in which the vice has proved decidedly-(s£?m- 
blement) prejudicial, providing, as is done in my part of the 
* Nachtrage zur Pathologisclien Anatomie, Von Guilt, p. 69. 
t Repertorium der Thierkeilkunde, herausgegeben von Hering; 1850, p. 190. 
