772 ANATOMY AND PHYSIOLOGY OF THE HORSe’s FOOT. 
different portions of the living surface perforin definite func- 
tions in the elaboration and constitution of the hoof while the 
organ is in its usual healthy condition, and though these 
functions are carried on actively and continuously so long as 
these parts preserve their integrity, yet it must be remarked 
that the production of horny matter does not belong solely 
and exclusively to them. On the contrary, and owing to a 
wonderful provision of nature, this faculty is common to all 
parts of the foot, and can be brought into operation at any 
given point when some change, or some extraordinary neces- 
sity for it occurs. We have mentioned that though the vas- 
cular laminae do not, in health, take an active part in secret- 
ing horn material, yet disease or accident will cause them to 
assume a particularly energetic secretory function which 
oftentimes leads to undesirable results. 
But the peculiar and striking susceptibility of the whole 
region to throw out this epidermic protection is made more 
particularly manifest after accidents, surgical operations, or 
experiments on the living portions of the foot. 
The hoofs of horses, like the horny formations of other 
animals, may be, either through the effects of accident, or of 
local or general disease, removed in a slow or sudden manner 
from their adherence with the living tissues, leaving these 
exposed. This, even under the most favorable circumstances, 
is a serious occurrence, from the length of time necessary for 
a new and efficient hoof to be reproduced, and the care re- 
quired to prevent the keratogenous membrane from becoming 
so injured or altered that its function may be modified or 
altogether destroyed. The latter result most frequently 
follows accidents in which the hoof has been violently torn 
from the living parts beneath, and these have been irreparably 
injured, either in the act of separation from the horn, or by 
subsequent bruising and laceration. 
But provided they are not seriously involved, and care and 
patience are exercised for a certain period, the hoof will be 
reproduced, and, in some instances, almost as perfectly and 
in as efficient a condition as the previous one.* Cases of 
# A good example of hoof reproduction, after an accident, is given by 
Mr. Cartledge, of Sheffield, in the Veterinary Record for 1845. In 1844, 
a mare, five years old, was at work on the railway at that town, drawing 
waggons filled with earth. In order that the waggon might be ‘ tipped 5 
or emptied of its contents into a pit at the proper spot, the velocity had 
to be increased to a rapid pace for sixty or eighty yards, and it was after 
exerting all her force and speed to give the waggon the necessary mo- 
mentum, and the mare was being suddenly removed from the path in order 
that the carriage might pass on, that her front foot — the right — became 
wedged in between the ends of two iron rails, sufficiently apart to admit 
it ; the end of one rail was inserted between the sole and the toe of the shoe. 
