CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 129 
some persons’ estimation, most of the foreign horses do, and yet 
prove insecure upon his legs, or he may go close enough almost 
to kick up seven-shilling pieces, and yet prove a safe hackney, of 
which T very well remember an instance in a mare, a cover hack, 
belonging to Capt. P., who, notwithstanding she appeared to raise 
her feet hardly oyster-shell height from the surface, dashed along 
at a good ten-mile-an-hour trot, without — as the Captain has often 
assured me — ever making a mistake. I do not make mention 
of these acknowledged exceptions to general rules that have been 
laid down by writers on action with a view of casting any dispa- 
ragement on these laws, but to shew that horses will go well and 
safely in many ways different from those which are prescribed, 
and in so many different modes, that, to set about to frame rules 
for action, to say a walk should be performed in this manner, and 
a trot in that manner, is more, I think, than any man who had 
in his time ridden many horses would pretend to do. Even Sol- 
leysell, who may be regarded as the original framer of these rules, 
after telling us how a horse should raise his foot, “ so as not to 
cross one leg over the other,” and how he should sustain his limb, 
so as properly to poise his body, and how he should put it flat 
down, “ the whole foot equally at one and the same instant of 
time,” admits still that “ there are some horses which, although 
they have the raising, keeping up, and tread of the foot very good, 
yet have they a had walk” 
CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 
By JAMES Mercer, M.D., Fellow of the Royal College of Sur- 
geons, and Lecturer on Anatomy, tyc. Edinburgh . 
On Congenital Malformations of the Hip Joint. 
The various abnormal appearances presented by the different 
articulations are the results of one of three operating causes, viz. 
causes operating previously to birth, and giving rise to a congeni- 
tal malformation in their mechanism and functions ; secondly, the 
effects of disease ; and, thirdly, the results of accidents. Numerous 
examples are daily afforded, both in man and in the lower animals, 
of the two last conditions, but of the first the instances are very 
rare in both classes; when any such cases, therefore, do occur, in 
either of them, a record of their morbid appearances cannot but be 
interesting to the practical pathologist. 
VOL. XVII. S 
