observations on soundness. 
279 
liorny substances—1st, the crust or wall, composed of longi¬ 
tudinal fibres closely matted together, which, when macerated, 
have the appearance of coarse horse-hair. This part of the 
hoof is elastic to a limited extent; it yields when the weight 
is thrown on it in a downward and backward direction; this 
elasticity is greater at the coronet and the quarter where the 
lateral cartilages greatly contribute to it, but it is almost nil 
over the os pedis. 2nd. The sole, which is composed of irre¬ 
gular layers superposed on one another. It does not, as far 
as I have been able to ascertain, possess any elasticity or 
yielding power. According to Bracy Clark, Girard, and 
other writers on the horse^s foot, the sole contributes to the 
elasticity of the foot by expanding the heels; this, in my 
experiments, I have been unable to discover, and I doubt it 
being the fact. 3rd. The frog, a soft pyramidical body, 
bifurcated at the base, and composed of flexible fibres, parallel 
like those of the crust or wall. Its function is to ward 
off concussion and prevent slipping. It is therefore neces¬ 
sary that it should always be brought in contact with the 
ground, as otherwise it will become hard and dry, and be 
thrown out of use. 
The horse^s foot, from its shape and construction, is essen¬ 
tially formed for rapid progression on plain or level ground. 
It is not like that of the polydactyls, adapted to ascend or 
climb, or even like the didactyls, to secure a footing on steep 
rocks or mountains, where they find food and security against 
hunters and beasts of prey. It therefore possesses great 
solidity and but limited yielding power. 
OBSERVATIONS ON “ SOUNDNESS.” 
By R. H. Dyer, M.R.C.V.S., Waterford. 
(Continued from p. 212.) 
The lateral cartilages are liable to become ossified, especi¬ 
ally in the heavy draught and coarse bred horses; and well 
bred ones are not entirely free from the disease. Many horses 
are the subject of this disorganization of structure, and are 
passed as sound, and free from disease, by the veterinarian ; 
in some instances by being overlooked, and in others, in con¬ 
sequence of the examiner not deeming it necessary to make 
any remark. Some men are desirous of earning the name of 
