INJURY CAUSED BY NON-PARASITIC ORGANISMS 61 



fornian disease is considered to be due to an allied organism, 

 P. californica (Viala and Sauv.). 



I have shown under the heading ' Orchid Spot,' that the 

 supposed organism considered by Viala and Sauvageau as a 

 member of the Myxomycetes, and named Plasmodiophora, is 

 merely a diseased condition of the cells of the host-plant, 

 and that brunnisure of the vine and ' orchid spot ' are 

 entirely due to physical causes. 



Massee, Ann. Hot., 9, p. 421. 



Viala, Ma lad. de la Vigne, Ed. 3. 



Viala and Sauvageau, Journ. de Hot., 1892. 



Strangling fungus (Thelefihora laciniata, Pers.) is an 

 exceedingly common fungus on heather tracts and in woods 



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FlG. 8. Thelephora laciniata, a non-parasitic 

 fungus growing up the stem and suffocating a 

 young larch. Reduced. 



and although not a parasite, it often proves highly injurious 

 to young trees when first planted, by growing up the stem 

 for some distance and enveloping the lower part of the seed- 

 ling to such an extent that it is strangled or suffocated. The 



