32 



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 only 

 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 ou the same individual, 



