132 
A. ZUNDEL. 
moisture, and once loose, is not renewed, the tissue producing it 
having lost its function of secreting the horny substance, and now 
secreting a serous element, which becomes the caseous matter of 
which we shall speak hereafter. 
Sometimes the disease begins by moisture in the hollow of the 
coronet, by a kind of grease , a disease which we shall see to be of 
the same nature as canker. There is an oedematous swelling, 
warm, somewhat painful, of the phalangeal region, first serous, 
then becoming opalescent, which seems to filtrate through the soft¬ 
ened, but not yet raised, epidermis. This inflammation, spreading 
little by little towards the hoof, extends to the plantar keratogenous 
membrane, and gives rise to an exhalation of the same nature as 
that of the skin, which produces the separation of the hoof, and 
the first marks of canker. 
Sometimes one may observe at once, a fungoid growth or 
ficus, formed by an hypertrophy of the tissues underneath ; this 
growth is more or less moist and offensive, bleeding easily, having 
the aspect of cauliflowers, and protruding through a break of the 
softened hoof, and forming a thready detritus to be subsequently 
studied. Commonly, the hoof is more or less loose, and under it 
there is a caseous matter, greasy, ordinarly of a foetid odor, easily 
removed by scraping, being non-adherent to the tissue which 
secretes it. If the parts are well cleaned from this, the velvety 
tissue of the pyramidal body of the frog appears to be covered 
with a smooth membrane of a slight whitish color; the external 
layer then appears formed by a pellucid epidermic covering, 
showing through its transparency the purplish color of the capil¬ 
laries underneath. The velvety tissue is diseased, but still retains 
its functions, which on the contrary are increased but perverted, 
and instead of secreting a horny substance which adheres to the 
surface of the keratogenous membrane, produces the caseous matter 
already referred to. The breaking in the hoof frequently seems 
small in size. Nevertheless, the alteration of the keratogenous 
tissue, viz: the substitution for its normal, of a pathological 
secretion, whose product is this loose caseous matter, is far ad¬ 
vanced. There is then an extensive, though a concealed separa¬ 
tion of the hoof. One then must not allow himself to be deceived 
