90 
M. CH. MARTIN. 
Cribbing with ingurgitation , or when the air does not go be¬ 
yond the pharynx, is in itself a serious vice, but accompanied by 
deglutition is much more so, because the air, after passing beyond 
the pharynx, follows the sesophagus, and entering the stomach, 
penetrates into the intestines. It is this form of cribbing which 
impairs digestion and nutrition, with consequent debility and 
emaciation, ending in premature death. 
The determining or efficient cause of cribbing is the depression 
and sudden dilatation of the pharynx, produced by the contrac¬ 
tion of the sterno-hyiodeus and sterno-thyriodeus muscles. These 
muscles do not act, it is true, immediately upon the pharynx, but 
their fixed point being at the sternum, their contraction lowers 
the hyoid and the larynx, to which the pharynx is so intimately 
connected that the hyoid and larynx can not be lowered and brought 
nearer the sternum without carrying with them in the same mo¬ 
tion, the pharynx. 
Before going further in the study of cribbing and of its 
occasional causes, let us examine closely a cribber, and initiate 
ourselves into the organic mechanism of this unnatural act, taking 
for type the cribbing with point d’appui which is most frequent. 
II 
The horse which cribs with pobit dhappui , seizes the feed-box 
or hay-rack with its incisives in order to immobilize its head by 
resting it; most commonly upon the superior incisors. In this 
position, the lips are wide apart and the mouth open; he then 
contracts suddenly all the flexor muscles of the neck, the sterno 
hyoideus and thyroideus muscles engaging in the same action, 
and drawing the pharynx inwards. This lowering motion elongates 
this canal, dilating it lengthwise, and the air that it may contain is 
thus rarified. It is at this moment that the atmospheric pressure, 
acting in the open mouth, the outside air raises the velum palati 
and rushes rapidly into the pharynx, thus producing that noise 
which is nothing more than the effect of the collision of the air 
upon the pharyingeal walls. 
The mouth being wide open , the sudden contraction of the 
sterno-hyoideus and thyroideus muscles , the lowering of the phar- 
