LAMENESS IN HORSES. 
243 
disease, the healing of one being so often followed by fresh 
eruption in another. 
The Symptoms of Canker, in other words, the appear- 
ances presented by a foot in a state of canker, are at once pe- 
culiar and striking. The diseased foot has that strange loath- 
some aspect which may suggest a fanciful comparison of it to 
a crab or a toad, or any other unsightly or anomalous thing. It 
looks as though it hardly belonged to the leg ; as though, in fact, 
it never could have been included within the confines of the 
hoof. With its fungous growth sprouting from it, wherever it 
happens to be bare of hoof, it conveys to our mind a notion that 
it is in a state of luxuriance or hypertrophy. This is sup- 
posing we do not see the foot until canker is fully developed in 
it. Had we happened to have seen it at the beginning, or 
could we obtain the history of the case, we should almost in- 
variably find that the germs of the disease were first discover- 
able within the cleft of the frog. This cavity becomes the 
fomes of corruption and decay. At its bottom and around its 
sides are visible, shreds of dark-coloured, dead and partly 
loosened portions of horn, which have become detached from the 
living surfaces beneath by an acrid serous exudation from the 
latter, which is everywhere oozing through the crevices of the 
dead and semi-detached horn, the partial solution of which by 
it has in places rendered the fluid black, and from its becoming 
at the same time putrescent, intolerably offensive to the smell. 
When we come to remove this discoloured and decayed horn, 
and expose the sensitive surfaces, we find the latter covered 
with an opaque whitish caseous matter, supplying the place of 
what naturally should be fresh-secreted horn ; but which is evi- 
dently in important respects different from it, as well in its aspect 
as from its property of continuing softness, and consequent un- 
fitness for the purpose of cover or protection to the living sur- 
faces. No sooner, however, is the resistance or pressure afforded 
to the secreting parts (so long as it remains) by the old horn 
removed than fungus sprouts from the bare and exposed surfaces. 
FUNGUS, which may be said to constitute the essence of 
canker, is a white, soft, consistent substance, of fibrous compo- 
sition, growing in such exuberance from the diseased surfaces 
that it not only occupies the place of the horny covering, but 
swells to a bulk much beyond the ordinary boundaries of the 
hoof, having its surfaces covered with layers of the foetid caseous 
matter but now mentioned, while its fibres and crevices are 
bedewed with the nasty ichorous secretion which, from solution 
of any old horn remaining, turns black around the roots of the 
fungus. From the granulary aspect the fungus ordinarily as- 
sumes, some have regarded it as a sort of exuberance of granu- 
