THROMBOSIS OF THE ILIAC ARTERIES. 
165 
this to be a very rare disease in actual practice. I personally 
have but little experience, and that only while at college, with 
a few cases in the live animal, but in the dead subject in the 
dissecting-room we find it different. 1 think while at college 
that about one out of every twenty of the plugs used for that 
purpose exhibited thrombosis, and that too in vessels in most 
instances of considerable size. One case I remember in the 
post aorta, near its origin, but the majority of them occur¬ 
ring in that vessel at its termination, or involving the iliac 
arteries. The museum of the college also contains many in¬ 
teresting examples of this disease. It seems to me, therefore, 
from its frequency in these dead subjects, that during life the 
trouble must frequently remain unrecognized, or probably be 
the cause of many obscure lamenesses or diseases. I should 
like to hear the views of members present, and their experi¬ 
ences as to the frequency of its occurrence in practice. 
I will only briefly consider the pathology of thrombosis or 
embolism, as it might occur in any blood vessel, and then 
give the symptoms as exhibited, especially when affecting the 
post aorta or iliac arteries. 
Regarding the pathology, I extract from Williams that a 
thrombosis is the coagulation of the blood in the vessels, 
be it arteries or veins. It may proceed from inflammation of 
vessels, caused by some injury, the result of this being an ex¬ 
udation from the walls of the vessels, forming the nucleus of 
the clot. The formation of the coagulum always begins at 
some definite, fixed spot, which is the source of local irritation, 
and from this it extends until the artery is plugged up to its 
origin from the parent trunk. Portions of this clot or throm¬ 
bosis may often become detached from the walls or valves of 
the blood-vessel, and be impelled onward to other parts of 
the circulation, being then termed an embolism. Thrombi 
may be impelled from the heart to the arteries, or may form 
in the veins and travel to the heart; as long as the thrombosi 
is confined to a branch vessel, there is no particular danger. 
But the greater number of trombi in the small branches do 
not content themselves with advancing up to the level of the 
main branch, but new masses ol coagulum deposit themselves 
