DISEASES OF THE SKIN AND SUB-TISSOES. 298 
Cases, however, will sometimes occur which set at defiance al) 
our skill, In such we find that either the ligamentary, tendinous, 
or fleshy parts, or perhaps the bones, are involved, and it often 
happens that fistulas or pipes run in various directions. Such 
cases require the services of a surgeon, who will dissect out the 
fistulous pipes, and remove all the diseased portions of the flesh 
and bone. The after-treatment is then the same as we have just 
indicated. 
FistuLous WITHERS. 
This disease resembles poll-evil, and, in a majority of cases, 
uwes its origin to the same exciting causes; namely, external 
bruises, or injury inflicted by a bad-fitting collar or saddle. The 
treatment is the same as that recommended for the cure of poll- 
evil. 
WARTS ON THE SKIN. 
Warts are of two kinds. One of these makes its appearance 
upon, and consists in part of an increased development of, the 
outer scurf or scarfskin ; the other kind is contained under, and, 
while it elevates, does not grow from the scarfskin. As it fre- 
quently becomes desirable to remove these growths, and to coun- 
teract that condition of skin on which their reproduction depends, 
we shall briefly describe them. The most common kind of wart, 
and that called the true angleberry, is the first of the two to which 
we have alluded. It has always a hard, horny sort of investment 
externally. This is formed of scales of scarfskin matted together 
in great quantities, and prolonged from the true skin, to which 
they are attached. As this outer covering increases in growth, it 
dries and splits up into shreds or fibers, which generally occome 
more or less pointed at their free ends. Many of these shreds 
may grow from one common stock or pedicle, called the “neck.” 
In other cases there is wo well-defined neck, and a large surfac 
will be covered with a coarse, rough, and horny crop of warts, all 
as it were, united where they originated from the skin. 
Cause.—W arts are always produced from what may be consid- 
ered as greatly-developed knots, or papille, within the true skin. 
Blood, in greater quantities than natural, is sent to these, and the 
papilla continuing to grow, forms perceptible tumors, which are 
somewhat sensitive, painful if exposed to friction, and form w 
