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I believe this to be the reason of the obstinacy of the 
disease; the mycelium had burrowed deep down into the 
skin, beyond the reach of ordinary parasiticides, and thence 
sent to the surface the spore-bearing filament. The cuticle 
was repeatedly destroyed by both carbolic and nitric acids 
without the destruction of the parasitic plant. 
Taking this view of the subject, I venture to suggest that 
the true mode of attacking these plants will be found to be 
by sealing them up, whenever they appear, from the action 
of light and air, the two necessities of plant growth ; but, 
as it is known that fungoid growths require a larger supply 
of oxygen than the flowering plant, partaking more of the 
nature of animal life, the exclusion of air ought to be of 
especial benefit. I am now trying an old remedy which 
ought to have this effect of excluding light and air, viz., 
varnishing the affected part with a thick coating of tar 
varnish, but I cannot as yet speak of the result. 
I had intended to have given the result of my search 
after knowledge among the hand-books on the subject of 
skin diseases, but perhaps it will be sufficient to say that I 
found more confusion than knowledge, and that the onty 
safe conclusion I have as yet arrived at is that it is the 
imperative duty of every botanist and microscopist to do 
what in him lies to throw light upon this subject of vege- 
table parasites, which are not only disfiguring, depressing, 
and painful, but in many cases continue their growth for 
years on the same individual, 
