MEMOIR ON TENOTOMY. 585 
have been productive of such beneficial results in the hands of ex- 
perienced operators. 
For the present we shall confine ourselves to the consideration 
of plantar tenotomy, and at some future time make known to the 
Society, if they should think proper, the results of the experiments 
undertaken by M. Henri Bouley and myself for the removal of 
bowed legs in horses. 
That peculiar deviation of the bony shafts which, by their 
union, form the articulation of the fetlock — that deviation which 
procures for horses in which it is found the designation of knuck- 
ling, M. H. Bouley, in the course of clinical instruction given by 
him at the school at Alfort, advises should be studied under three 
separate heads or degrees; for the treatment pursued must depend 
entirely on the intensity of the disease. 
The first, or mildest form, is that in which the more or less ob- 
tuse angles formed in front by the cannon and pastern bones evince 
a marked tendency to disappear, and the region of the cannon bone 
and that of the pasterns, instead of representing a broken line, as 
it ought to do, present almost a perpendicular one. 
In the second stage, the angle of the fetlock, which, under the 
influence of causes we shall presently have to speak of, has gradu- 
ally become effaced, exists no longer ; and, not only so, but appears 
as if it would be formed again on the opposite side. At this pe- 
riod a very superficial degree of observation will enable us to per- 
ceive that, in almost all knuckling-over horses, the weight of the 
body is no longer thrown on the heels, but rests chiefly on the an- 
terior portions of the hoof. 
Lastly, the third stage is an exaggeration of the symptoms which 
we have already mentioned. The articulation of the fetlock is 
thrown so forward in consequence of the retraction of the flexor 
tendons, that the summit of the angle, the opening of which is now 
posterior instead of anterior, projects considerably beyond the line 
of perpendicular. It is almost impossible to work or use animals 
that are thus deformed in their legs. 
Before entering into a consideration of all the numerous causes 
which may give rise to this evil, we will, in as few words as pos- 
sible, describe the anatomical disposition of the part on which 
plantar tenotomy should be performed. Should we in this descrip- 
tion pass too rapidly over important details, it is because they have 
appeared to us to be thoroughly explained in the Essay published 
by Professor Delafond in 1832, on the section of the flexor tendons 
of the foot of the horse. 
The tendinous apparatus which is found adhering to the poste- 
rior surface of the cannon bone and phalanges, and which is intended 
to support a portion of the weight of the body, consists of the ex- 
ternal and the internal. 
