516 
LIVERPOOL VETERINARY MEDICAL ASSOCIATION. 
paid to his diet, and serious derangement of his digestive apparatus 
is the immediate consequence. Before dealing with indigestion, I 
shall endeavour to describe to you, in as few words as possible, the 
process of digestion. 
In the horse, as in all other domesticated animals, the digestive 
apparatus is constituted of a membranous and contractile canal, 
which extends under the vertebral column from the head to the 
posterior part of the body, or, in other words, from the mouth to 
the anus. This tube is lined by a mucous membrane, the organiza- 
tion and functional properties of which, in its abdominal section, 
are of the greatest importance, being the principal seat of the essen- 
tial phenomena of digestion ; whilst the other parts, such as the 
mouth, pharynx, and oesophagus, only serve to take, to prepare, 
and to introduce the alimentary materials. 
Digestion may be said to be the process by which those parts of 
the food which may be employed in the formation and repair of the 
tissues, or in the production of heat, are made fit to be absorbed, 
and added to the blood. Pressed by hunger and thirst, sensations 
which express the necessity of repairing the general and continuous 
waste of the system, the animal seizes the food which he meets 
with, or is given to him ; previously, however, he takes care to 
subject it to an examination by sight and smell. Once in the mouth, 
the sense of taste must be satisfied; whatever is offensive is rejected, 
the residue is ground down by the teeth, and, while undergoing this 
process, becomes thoroughly impregnated with saliva, and is thus 
reduced to a soft pulpy mass, which very much facilitates the next 
move, namely, that of deglutition, or the passage of the food from 
the mouth to the pharynx into the oesophagus, from thence to the 
cardiac end of the stomach, where it is mixed with a quantity of 
mucous, which prepares it to be acted upon by the gastric juice of 
the true digestive, or pyloric end of that organ ; by the agency of 
this fluid, and the movement of the stomach, it is reduced to a 
semifluid consistency, and converted into a uniform pulp called 
chyme ; it is then transmitted through the pylorus into the duo- 
denum, and there mixed with bile, and the pancreatic secretion 
and intestinal mucous. It is then in a fit state to have its nutri- 
tious portion taken up by the lacteals, which form a closed system 
of vessels upon the mucous surface of the intestines, and to be car- 
ried by them to the blood, while the indigestible or excrementitious 
part is moved onward by the peristaltic motion of the bowels, and 
in due time expelled by the anus. 
Having thus gone over, in a very brief manner, the healthy func- 
tions of the alimentary canal, I am brought to the more immediate 
subject of my paper, 
Indigestion . — In order that digestion may be perfect and easy, it 
is requisite that the food should be in a state of minute division. A 
weak stomach acts slowly or not at all, on tough masses of solid 
food, and horses, like men, have weak and dyspeptic stomachs. The 
greedy feeder swallows a great part of his food half masticated ; the 
cribber frequently distends his stomach and bowels with gas. In 
