LIVERPOOL .VETERINARY MEDICAL ASSOCIATION. 389 
“ annular ligament” at the back of the hock; and others the 
synovial sheath of the tendons of the “ perforans ” and “ perfora¬ 
te.” The differences of opinion recorded in early veterinary 
works, as the structure affected, is just as great as we find ex¬ 
pressed in more modern veterinary works upon the subject. 
Now I hope to be able, in the first place, to show you that 
there are no satisfactory reasons for accepting some of these 
theories, and, in the second place, I will endeavour to point out 
the true site of the disease. 
But in order to render my description as clear as possible, I 
will briefly describe the structures situated at the postero-inferior 
part of the hock. 
There are the tendons of the “perforans ” and" “ perforatus,” 
which at this point pass down in close proximity to each other ; 
there is the strong fibrous ligament at the posterior part of these 
structures, the so-called “annular ligament,” and the strong 
band of ligament extending from the apex of the os calcis to the 
cuboid and external metatarsal bones—“ calcaneo-cuboid” 
ligament. 
Is curb sprain of the calcaneo-cuboid ligament ? I answer no. 
This is one of the strongest ligaments of the body, its function 
being to assist in holding the calcis in its proper relative position 
to the other bones of the hock, and to deal with the strain put 
upon the calcis, wdiich is considerable at times, on account of that 
bone affording a point of leverage. 
Had this important structure become sprained—partially lace¬ 
rated—recovery would seldom or ever take place. But in addition 
to the calcaneo-cuboid, we find strong interosseous ligaments 
which assist in retaining the os calcis in its position, and I opine 
that any force which would bring to hear such a strain upon this 
part to lacerate the calcaneo-cuboid ligament, would also so 
sprain the interosseous ligaments as to set up an amount of in¬ 
flammatory action that would give rise to articular disease, and 
that would tend to make almost every case an incurable one. 
Then there is the position of the enlargement exactly opposite 
the lower extremity of the calcaneo-cuboid ligament. Now, why 
should it always occur here if it is the ligament that is affected ? 
The ligament is as strong here as at another part, and the strain 
upon it is no greater. 
Then, again, if this ligament be the site of the disease the 
enlargement would always be nearer the outer side of the hock 
than the inner, and my experience is that the enlargement, if 
anything, favours the inner side. 
But why should this ligament be supposed to be the site of the 
disease at all ? for in no post-mortem examination of curb that I 
have made have I ever found it in the slightest degree involved in 
the disease, which certainly would not be the case if diseased 
action had ever taken place in it, for in sprain of similar struc¬ 
tures, such as the superior sesamoideal ligament, we find an in¬ 
filtration of lymph into its structure, with considerable external 
