Horny Excrefcences of the Human Body. 105 
I {hall conclude this Paper by obferving, that the cafes of 
horns, as they are commonly termed, upon the human head, 
are no more than cuticular produ&ions arifing from a cyft, 
which in its nature is a variety of thofe tumors deferibed by 
Mr. Hunter under the general name of cuticular ineyfted 
tumors *. 
Thefe ineyfted tumors, when confidered as varieties of the 
fame difeafe, form a very complete and beautiful feries of the 
different modes by which the powers of the animal oeconomy 
produce a fubftitute for the common cuticle upon parts which 
have been fo much affe&ed by difeafe as to be unable to reftore 
themfelves to a natural ftate. 
* The principle upon which the produQ:ion of thefe excrefcences depends 
being once explained, the modes of preventing their formation, and removing 
them when formed, will be readily underftood, the deflruaion of the cyft being 
all that is required for that purpofe. This may be done before the tumor opens 
•externally, or even after the excrefcence has begun to (hoot out, and will be 
better effefted by diffeSion than efcharotics, fince the fuccefs of the operation 
depends upoRthe whole of the bag being removed. 
) 
Vol, LXXXI. 
P 
