208 DISEASES OF THE HORSE'S FOOT 
animal treading on the stumps of nails, from treading 
on an upturned shoe with the stumps of nails in situ, or 
from treading on an upturned toe-clip. It may also occur 
from an accidental prick with the stable-fork when ‘bed- 
ding up,’ or from casting part of a shoe when on the road 
and treading on the nails, in this case left sometimes partly 
in and partly out of the horn. 
‘Serious wounds of this description are also met with in 
animals engaged in carting timber from plantations in 
which brushwood has recently been cut down. This is, 
of course, from treading on the stake-like points that are 
left close to the ground. Hunters also meet with the same 
class of injury when passing through plantations or over 
hedge banks, where the hedge has just been laid low or 
cut down. 
‘ Apricultural horses also meet with severe wounds of 
this class from treading on an upturned harrow.’ * 
It has been remarked how strange it is that nails should 
so readily penetrate the comparatively hard covering of the 
foot. The matter, however, admits of explanation. One 
knows from common observation how easy it is to tilt a 
nail with its point upwards by exerting a pressure in a 
more or less slanting direction upon its head. This is 
exactly the form of pressure that is no doubt put upon the 
nail if the animal treads upon it when moving at any pace 
out of a walk. The foot in its movement forward tilts the 
nail up, and almost simultaneously puts weight upon it. 
The great weight of the animal is then quite sufficient to 
account for its ready penetration. 
In purely country districts cases of punctured foot are of 
far less frequent occurrence than in large towns. In the 
latter, animals labouring in yards where a quantity of pack- 
ing is done, or engaged in carting refuse containing such 
objects as we have mentioned, or broken pieces of earthen- 
ware or glass bottles, meet with it constantly. 
For the manner of causation of those wounds to the foot 
* Journal of Comparative Pathology and Therapeutics, vol. iv., 
p. 2. 
