THE HORSE’S FOOT. 
153 
II .—Pathological Anatomy .—When one examines the cartil¬ 
age affected with the necrosis proper of quittor, he always finds 
lesions in proportion to the intensity and the age of the dis¬ 
ease. It is seldom, however, that the portions of the cartilage 
which have undergone the green degeneration, constituting the 
caries, reaches more than one centimeter in extent; they have 
the form of a small plate, of a green color, ordinarily elongated, 
and adherent to the healthy parts of the cartilage by one of its 
extremities, that which is more forward and the deepest. Others 
have compared it to the green growth of a seed in germination. 
The points of the fibro-cartilage which are in immediate contact 
with the carious portion, have also a slight, pale greenish hue. 
These are already diseased; there is already a beginning of 
necrosis; in the remainder of its extent this exfoliation is sep¬ 
arated from the cartilage by a reddish, soft tissue, which also 
lines the inside of the fistulous tract. This fistula, which extends 
from the necrosed spot to the skin, is but the hollow tract left 
by the diseased process upon the cartilage, while gradually de¬ 
stroying its substance. Always lined with a pseudo-mucous 
membrane, by a true pyogenic apparatus, the fistula is often 
narrow, sinuous, irregular in its course and in its extent, es¬ 
pecially if the disease is of some standing. 
Renault, and after him Lafosse, have mentioned a special al¬ 
teration of the fibro-cartilage which is sometimes met, and which 
Lafosse looks upon as a step towards recovery. It is a softening 
of the tissue, anatomically characterized by a loss of the con¬ 
sistency of the cartilage, resembling the case of the cellular 
tissue becoming indurated, or that of bones deprived of their 
earthy salts after soaking in weak acids; its yellowish color is 
then characteristic. It may be noticed during life, and is recog¬ 
nized by a softening in the region of the cartilage, which then 
yields, giving easily to the pressure of the finger. Besides this, 
a probe introduced into the fistulous tract readily penetrates 
into the softened substance. But the true way to diagnosticate 
this change consists in raising the coronary band or after thin¬ 
ning the wall; then one will see and may feel the true nature of 
the transformation. Lafosse adds that, in presence of this altera- 
