133 
THE HORSE’S FOOT. 
into supposing it to be a limited diseased process, by the apparent 
external integrity of the horny box. 
The characteristic of canker is its tendency to spread, like 
cancerous affections. Once manifested in any part of the 
sub-horny tissues, the special changes which characterize the 
disease seldom remains circumscribed; on the contrary, they 
generally extend from that part as a centre, throughout 
the whole circumference, and little by little, attack slowly 
but continously the whole extent of the secreting apparatus, 
and thus loosen the entire horny box — starting from the 
median lacunae, or the glomes of the frog, it extends to the 
branches and the body of the plantar cushion ; then spreads at 
the side, in the lateral laminae, from there all round on the velvety 
tissue, then by degrees reaches the inferior extremity of the 
podophyllous laminae and going upwards, reaches the coronary 
band, the last point, where, in extreme cases, the hoof preserves 
its adhesions with the tissues which form it. In this condition 
the diseased process progresses more slowly than between the sole 
and the velvety tissue, and then it seems to remain stationary; 
otherwise the dropping of the hoof would be possible. 
We have seen that often at the beginning, but especially as 
the disease progresses, there are growths called fici, found prin¬ 
cipally round the laminae, the frog and the sole. These are of 
whitish color, opal, varying in size and in shape; they constitute 
an irregular mass, formed of those fici pressed together; some of 
these growths have a wide basis, others are somewhat peduncu¬ 
lated ; sometimes they are single, tubercular, slightly elevated ; 
at other times elongated bodies, true fibrous bundles. The fici are 
nothing more than the normal villosities of the keratogenous tis¬ 
sue which have become tumefied and hypertrophied, and are found 
principally where, in the normal state, the villosities of the vel¬ 
vety tissue are themselves more numerous and more developed. 
Where these vegetations are confluent, as upon the sharp edge of 
the bone, they are separated from each other by a kind of deep 
sinuous grooves, filled with the caseous matter secreted by the 
diseased keratogenous structure. These growths bleed easily and 
grow rapidly again when excised. Those most developed, and 
