398 
Lamenesses of Sheep and Lambs. 
ascribed to flics depositing their larvae about the interdigital 
space, and the maggots, which in hot weather infest manv^ases 
of foot-rot, are referred to in support of this view. But these 
maggots are an accidental consequence of the disease, and not 
the cause of it. Others have thought that foot-rot was produced 
by minute parasitic animalcula, which were developed on certain 
pastures, attached themselves to the feet of the sheep, and in- 
duced irritation and inflammation. But there is no proof of the 
existence of any such creatures. Mr. Spooner in his 'History, 
Diseases, &c., of Sheep,' says, " it consists of inflammation and 
suppuration, and often ulceration, of the sensible and secret- 
ing parts of the foot, and results from contact with vegetable 
bodies in a state of putrefaction." The definition of the disease 
is good ; the explanation of its production is very insufficient. 
No doubt if sheep stand much upon decaying vegetable matter 
their feet become soft and liable to the disease, in the same way 
as if kept upon any soft moist pasture. But the decaying vege- 
table matter is only one of the many causes of foot-rot, and by 
no means one of the most common. 
Foot-rot is liable to be produced in many different ways, and 
by the most dissimilar causes. It often results from the over- 
growth of the hoof, and the turning in of the toe, pressing upon 
and irritating, the sensitive lamina?. This is especially apt to 
occur amongst sheep brought from indifferent upland pastures 
to rich meadow lands. Hence the notorious prevalence of the 
disease amongst l)lack-faced, Cheviot, and South-down sheep, 
carried from their native walks into rich arable districts. On 
their native grazings the surface of the soil is usually rough and 
rugged, whilst the grass is not over-abundant, and the sheep 
have therefore to stray considerable distances before they can 
procure a sufficiency. Under such circumstances, the produc- 
tion and waste of the horn are fairly balanced. When, however, 
such sheep are transferred to smooth, well rolled, rich lands, 
or to soft, moist, luxuriant meadows, the abundance of food 
removes the necessity of much walking, the tear and wear of 
the hoof is accordingly reduced, the horn shoots out in exu- 
berant quantity, and usually also of less compact structure, 
while the sole also usually becomes convex, causing much pain, 
and the production of troublesome ulcers. The crust hence be- 
comes liable to laceration, and the sensitive parts of the loot are 
thus exposed to mechanical irritation, as well as to the injurious 
influence of extreme cold, heat, and moisture. Again, the over- 
growth of horn and consequent lengthening out of the toe, injures 
the foot in another way. It exposes the sensitive lamina^ to un- 
wonted strain, and thus renders them weak and unfit for the 
secretion of healthy horn. A softened, spongy, and degenerate 
