260 IRISH CENTRAL VETERINARY MEDICAL ASSOCIATION. 
The large intestines are twenty-three feet long, and are subdivided 
into the caecum, colon, and rectum. They are composed of three 
coats, one external or serous, middle muscular, and internal mucous 
coat. 
The serous, peritoneal, or external coat is attached to the muscu- 
lar by cellular tissue, and contains numerous blood-vessels, lym- 
phatics, and nerves. 
The muscular coat is composed of two layers of fibres, a longitu- 
dinal and a circular. The longitudinal fibres cover all the small 
intestines. In the large they form bands, which draw the intes- 
tines into pouches, except upon the apex of the caecum, and also a 
portion of the rectum, where the fibres collect together at the pos- 
terior part of the rectum, and form a muscle called the internal 
sphincter ani. The mucous coat is also connected to the muscular 
by cellular tissue, and in the small intestines is studded by numer- 
ous very vascular villi of a conical shape, each one containing a 
rootlet of the absorbent vessels in its centre. 
Glands are situated in the submucous tissue of the duodenum 
called Brunner’s, or Racemose. Lieberkiihnian follicles are found 
throughout all the intestines, and also small ductless glands. Soli- 
tary glands are found in the large and small intestines, and Peyer’s 
patches in groups in the jejunum and ileum. 
The mucous membrane in parts is thrown into folds which form 
valves ; one exists at the opening of the ductus choledicus commu- 
nicus vel pancreaticus, and one at the entrance of the small intes- 
tines into the large, called the ileo-csecal valve. 
The mucous membrane of the large intestine has no villi. 
Spasmodic Colic , as the name implies, is spasm of the muscular 
coat of the intestine, and is, as a rule, confined to the small, but it 
may and does attack the large intestines ; in these cases it is only a 
secondary disease brought on by distension of the bowels with gas. 
Causes . — Food to which the animal has not been accustomed, or 
food eaten rapidly after a long fast, or before fast work, for at that 
time the digestive organs are very vascular, consequently more irri- 
table ; large draughts of cold water when the animal is heated ; 
costive bowels, by exciting irritation ; calcareous concretions, or 
other offending bodies ; tumours in the mesentery ; intussusception, 
stoppage of the biliary duct, &c. ; in fact, anything that will excite 
irritation of the muscular coat will cause colic, especially where 
there is a constitutional tendency. 
Symptoms . — The animal becomes uneasy ; if at work he will stop 
or go faster, scrape with the fore feet, look round to his flank, kick 
violently at his belly, shift from side to side, draw all four legs 
together, lie down, roll, get up, shake himself, and then he may eat 
a little. Probably he remains easy for some time ; then he begins 
as before to evince signs of pain, but of a more violent character 
than the preceding ones ; perspiration rolls off him ; he throws 
himself on his back, in which posture he will often remain for some 
seconds. These symptoms may continue off and on for a consider- 
