370 
T. F. WINCHESTER. 
which is, of all the intestinal divisions, the most liable to throm 
boses and embolisms. Paralysis of the intestine often bring 
about rupture of it, the stomach, or the diaphragm, owing t< 
fermentation and enormous accumulation of matter and ga 
therein. 
In animals which have been cured of colic for some time 
old lesions in the form of thromboses are often found in th< 
branches of the great mesenteric artery, as well as in the coi. 
responding veins, these vessels being partially or totally oblit 
erated, and around them pigmentation of the peritoneum anc 
other organs is usually observed. Bollinger says that on ;] 
square centimetre of surface, there are sometimes found fiv< 
or six arterioles or veinules so obliterated. 
At the autopsy of horses which have died from colic, it i: 
often difficult to discover the obliterated artery and the sea 
of the embolus, because of the great development of the in 
testinal vessels, and more especially on account of their con 
gested conditions ; so that care and patience are needed in 
this search. 
The effects of the aneurisms, the thromboses, and the era 
bolisms, are evidently subordinate to their situation. Th( 
presence alone of the aneurism and its clot reduces the calf 
bre of the great mesenteric artery, and consequently diminj 
ishes the supply of blood to the intestine; this is sufficient to 
explain the chronic indigestion troubles observed, and these 
effects are all the more marked if the diminution in the lumei 
is extended to a ramification, but they are especially so if the 
vessel becomes completely obstructed by a detached fragj 
ment of the thrombus. But as the arteries of the small in 
testine anastomose freely by inosculation close to the concave 
curvature of the organ, embolism of one of the vessels isj 
never a fatal accident. It is the same with obliteration of one 
of the two caecal arteries; for the other, which anastomoses: 
with it near the point of the caecum, can assume its function 
so that the attacks of colic pass off. But if the trunk of the 
right fascicuus of the great mesenteric artery is completely 
obstructed, the caecum does not receive any blood, and death 
quickly ensues. $he large colon receives its blood by the 
