200 DISEASES OF THE STOMACH AND INTESTINES. 
diarrhoea, not, however, of a serious character, as the abnormal 
condition here consists rather in the altered condition of the 
evacuations than in any excess ; the great cause of exhaustion 
is, therefore, absent. 
A generally irritable state of the membrane, which renders 
it particularly susceptible to excitement, even from the 
contact of the ingesta, will lead to excess of secretion and 
diarrhoea; in these cases the symptoms are increased upon 
the consumption of any indigestible or stimulating food, and 
also by exposure to atmospheric changes. 
Local excitement from ulceration of any portion of the 
intestinal membrane, or from disease of the mucous glands— 
those of Peyer being frequently found in a morbid condition 
in dysentery in the human subject—may lead to an extension 
of the irritation in a degree proportioned to the development 
of the local disease. 
Derangement of the liver may be considered as the most 
constant cause of chronic diarrhoea, particularly in cattle; 
and, considering the function of the gland as an organ of 
elimination, there is no cause for surprise in the circumstance 
of a diseased condition of its secretion producing disturbance 
of the intestinal fluids with which that secretion is imme¬ 
diately combined ; we should naturally expect that organic 
disease or functional disturbance in the liver would lead to 
impairment of the digestive process, and ultimately to a 
depraved condition of the blood, and, by consequence, of all 
the secretions. 
Chronic diarrhoea from debility of the vessels and secreting 
follicles of the membrane is not uncommonly noticed in ani¬ 
mals suffering from anaemia, a tendency to diarrhoea from the 
action of insignificant causes being one of the concomitants 
of this condition. 
Irritability of membrane is apparently perfectly compatible 
with good condition, appetite, and general health, a fluid 
state of the evacuations being often the only indication of 
disease present. It is fair to conclude that an uninterrupted 
continuance of this element would occasion systematic dis¬ 
turbance, but that it may exist for some weeks without 
perceptible mischief is practically certain. 
Ulceration of the membrane we have occasionally met with 
in cattle after a protracted continuance of so-called dysentery 
(rot), and once by accident in an old horse, with whose 
history we are unacquainted. Whether or not disease of the 
glands may be a cause of diarrhoea has not been determined 
by veterinary pathologists, although there is every probability 
that such is the case. Ulceration, it is stated, is indicated 
