470 
DR. BYRNE. 
gestion, I shall endeavor to describe to you in as few words as 
possible, the process of digestion. 
In the horse, as in other domestic animals, the digestive appa¬ 
ratus is constituted of a membraneous and contracted canal, which 
extends under the vertebral column from the mouth to the anus. 
This tube is lined by a mucous membrane, the organization and 
functional properties of which, in its abdominal section, are of 
the greatest importance, being the principal seat of the essential 
phenomena of digestion ; whilst the other parts, such as the mouth, 
pharynx and oesophagus, only serve to take, to prepare and to in¬ 
troduce 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 ab¬ 
sorbed 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 secures 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 impreg¬ 
nated with saliva, and is thus reduced to a soft pulpy mass, which 
very much facilitates the next move, viz., 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 semi-fluid consistency, and con¬ 
verted into a uniform pulp called chyme; this is then transmitted 
through the pylorics into the duodenum, and then mixed with 
the bile, and the pancreatic secretion and intestinal mucous. It is 
then in a fit state to have its nutritious parts taken up by the lac- 
teals, which form a close system of vessels upon the mucous sub- 
face of the intestines and to be carried by them to the blood, 
while the indigestible or excreinentitious part is moved onward 
