4 
LAMENESS IN HORSES. 
the parts around, and so confined in its place. In front of the 
tendon, in the midst of this enveloping tissue, is a serous bursa ; 
while behind it, between its cellular investment and the skin, is a 
tendinous band to which has been given the name of annular liga- 
ment, whose glistening fibres are seen traversing the tendon evi- 
dently for the purpose of binding it down, and so in action contri- 
buting not a little to its power and effect. 
Now, if we, bearing this anatomical sketch in view, revert to 
the seat of curb, we shall find that the site of the tumour is directly 
opposite to the bursa in front of the perforatus tendon. Through 
this bursa or thecal cavity runs the perforans tendon, and it is the 
play the tendons enjoy at this particular part, in consequence of 
the existence of the bursa and the looseness and paucity of their 
attachments, that causes sprain or laceration to be seated here ; the 
part sprained or lacerated being neither the tendon nor the ligament, 
but the cellular sheath of the tendons. When curb is manifested 
as the immediate consequence of the wrench or sprain, we must, 
to account for such speedy tumefaction, suppose that bloodvessels 
are ruptured, and blood extravasated. More commonly, however, 
an interval elapses ere the swelling rises, and in that interval effu- 
sion takes place, of, no doubt, the ordinary sero-lymphy deposit, 
and this probably pervades cellular tissue and bursa together. 
This is accompanied — indeed is caused — by inflammation of the 
parts, which account for the heat, and the pain or lameness. The 
circumstance of inflammation not immediately following the acci- 
dent accounts for lameness not shewing itself in all cases at first. 
Indeed, in some cases the injury sustained appears too slight to bring 
it on : palpable curb exists, the horse remaining all the while per- 
fectly sound. What ultimately takes place in curb, and, in fact, 
constitutes the disease in the ordinary, inveterate, or permanent 
form, being the consequence of interstitial deposit, is a hard, callous 
condition of the tumour, and this is the state in which horses are 
brought to us after inflammation has departed. It consists in a thick- 
ened and indurated condition of the cellular sheath of the tendons. 
Therefore, when we come to dissect curb in this, the usual state of 
parts, what we find is this: We first cut through the skin cover- 
ing the tumour. This exposes the annular ligament; underneath 
which is the consolidated and thickened sheath, fibrous perhaps in 
composition, altogether changed in aspect and texture from what it 
was, and measuring, as I have seen it, half-an-inch across in solid 
substance. A curb, therefore, might very properly be said to con- 
sist in hypertrophy of the sheath of the flexor tendons. Doubt- 
less, there occur 
Other morbid Appearances. — Diseased action may conti- 
nue, or return, or be reproduced, and so give rise to them. Mr. 
