ON HOCK LAMENESS. 
6*69 
but, on the contrary, shews that he is not aware of, or that he has 
overlooked the fact, that lameness may arise from inflammation 
in bones, although one of the effects of that inflammation 
(exostosis) may not have so extended as to interfere “with any 
joint.” I have thus gone back to Mr. Spooner’s first cases, be- 
cause, in his reply to my remarks, he has referred to them, and I have 
only noticed the fourth of these cases, being the one, I think, he 
particularly alludes to in his last letter as his first case ; the other 
three being what is generally allowed to be common varieties of 
spavin, and not entitled to be ranked as “ obscure hock lameness.” 
In the account of that case no mention is made of the middle pro- 
tuberance of the tibia having the appearance of being worn down , 
nor are these words used in his July communication, neither does 
the plate you have given convey any such idea ; and I am there- 
fore persuaded such appearances were not presented in the pre- 
paration. In the last paragraph of my letter I have stated that, 
if these varieties arose from friction, they must have extended 
over the remaining part of the articular surface, by the pressure 
and friction being increased, and falling on the remaining sound 
surface. [This passage is a little obscured by a mistake of the 
printer, who has, at the end of the fifth line and beginning of the 
sixth in that paragraph, printed “the exertion” instead of “their 
existence,” (that is, of the cavities) as I had written.] 
Mr. Spooner endeavours to answer my arguments in this by 
two suppositions : first, he supposes that my arguments are right, 
namely, that the parts beyond the cavities would receive the 
pressure and friction, and therefore, even if they existed in all 
hocks, he would be right : but has he shewn that these cavities 
are enlarged ? No. Has he shewn that the cavity in the centre 
of the middle protuberance of the tibia has been produced by its 
being “ worn down ?” Most certainly not. But he secondly sup- 
poses that where there is no cavity a bruise takes place, and 
further supposes a great variety of circumstances, and thus builds 
a fine-spun theory upon his suppositions. But where is the 
proof ? I deny the soundness of his suppositions. Does he sup- 
pose that the middle protuberance of the tibia is a wedge to split 
the astragalus in pieces? or does he suppose the pressure between 
these bones is circumscribed to a fine point ? Does he suppose 
the protuberance of the astragalus is not exposed to pressure and 
friction as much as the other ? or to what extent does he suppose 
these parts are affected at the moment the centre is bruised ? I 
do not admit that any such bungling mechanism is to be found 
in the joints of any animal; it were a libel on the Author of 
Nature even to make such a supposition ; and on common sense, 
to assert that a mere mechanic, if shewn the hock joint, would 
VOL. x. 4 R 
