205 
CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 
By JAMES Mercer, M.D., Fellow of the Royal College of Sur- 
geons, and Lecturer on Anatomy, fyc. Edinburgh. 
[Continued from p. 141.] 
IV. — On the Structure of the Synovial Sulci of the Hock, and 
Ginglymoid Joints generally, in the Horse. 
In The Veterinarian for December 1830, Mr. W. C. 
Spooner, of Southampton, published a paper on Hock-joint Lame- 
ness, and which he then attributed to be produced by the abrasion 
of the articular cartilage on the central convex ridge of the inferior 
extremity of the tibia, accompanied with a corresponding change 
at an opposite point along the central groove of the astragalus. 
For several years no notice seemed to have been taken of the 
matter; and accordingly, in the July Number of 1837, he again 
reverted to the matter, and succeeded in drawing a reply from 
Professor Dick. This was followed by a very wordy, pithy, and 
sarcastic paper- war, in which two opposite opinions were most 
stoutly maintained; the one, that it was a positive pathological 
condition of the joint, and the other, that it was only a normal 
structure, and that similar conditions of the articular cartilage 
were found in many others, if not in all, of the articulations of the 
skeleton. Considering the matter, therefore, as one of some little 
importance, I directed my attention to it in making some recent 
zootomic investigations; and without being biassed by either of 
the above opinions, I carefully examined the subject of dispute, 
and now lay the few following remarks before the veterinary 
profession as to the results which 1 have obtained, and with the 
distinct hope that they will only be viewed by the practical vete- 
rinarian as the result of such, and not as a positive ipse dixit , to 
guide him in his practice or his opinions on a case of doubt or 
difficulty. 
In the first place, I may state that I have, with Rigot*, Fer- 
gusont, Youattf, &c. found these synovial sulci in many other 
animals besides the horse, and in those too where there had never 
been exhibited the slightest symptom of lameness ; and with 
Professors Dick and Rigot, I have also found them (uniformly, so 
* Traite des Articulations du Cheval, Paris , 1827, prim. chap. 
+ Veterinarian, vol. x, p. 492. 
X Loc. cit. sup. 
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