366 OSSIFIED CARTILAGES. 
if thrush simply interferes with the action, although it endanger the 
safety of the rider, it is, by the code of veterinary legislation, esteemed 
no reasonable objection to the soundness of a horse. In the author's 
opinion, any animal should be esteemed unsound which has suffered 
from loss of or from change of any structure that ought to be present, 
or has any affection which reasonably could subject it to remedial 
treatment. 
OSSIFIED CARTILAGES. 
This signifies a conversion into osseous structure of the cartilages 
naturally developed upon the wings of the coffin-bone, or the bone 
of the foot. Here is a drawing of the largest specimen of this trans- 
formation which the writer ever witnessed. 
This was borrowed from the museum of 
T. W. Gowing, Esq.; and, from the mag- 
nitude of the disease, the writer should 
imagine the posterior of the pastern must 
have been in the living animal somewhat 
deformed. 
SPREE? RANGA SES: In heavy horses, working upon London 
eee eee ee, eae acl bree stones, so certain are the cartilages to be- 
Pe ae aaa the come ossified that several large firms pay 
no attention to this defect. They prefer 
an animal with a confirmed disease to a sound horse, which will be cer- 
tain to be ill during the change, and the extent of whose subsequent 
alteration no one can predicate. So far these purchasers act wisely; 
but, in horses designed for fast work, ossified cartilages are a serious 
defect. They frequently occasion lameness, and always interfere with 
the pleasantness of the rider’s seat. When accompanied by ring-bone, 
ossified cartilages give rise to the most acute and irremediable lameness. 
Ossified cartilages are incurable. No drugs can force Nature to re- 
store the original structure which has been destroyed. Once let a car- 
tilage become ossified, and it remains in that condition for the creature’s 
life. There is little difficulty in ascertaining when this change has taken 
place. The hand grasps the foot just above the coronet; the fingers are 
on one side, and the thumb upen the other. The cartilages lie at this 
place, immediately under the skin. Cartilage is soft, pliable, and semi- 
elastic. It yields very readily to pressure. However, when the thumb 
and fingers forcibly press the part, if, instead of feeling the substance 
under them yield, the hand is sensible only of something as hard as stone, 
or any way approaching to such a character, that is proof positive the 
