WOOD SOIL CONTACT CULTURE TECHNIQUE 



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of Waterman and Williams'^ (1934) was used for the field tests at Gulf- 

 port, Mississippi. Table 2 shows the results obtained with the petri dish 

 method on the toxicity of four common inorganic salts and a creosote to 

 several of the usual test fungi. 



Table 2 



Toxicity Expressed in Per Cent Toxic Agent Present in Notrient Agar as 



Determined by Petri Dish Assay 



Resistance of the fungi to the four salts is variable, but it will be noted 

 that Lenlinus lepideus, which is most sensitive to copper sulfate, tolerates 

 the highest concentration of creosote. Poria incrassala, which is fairly- 

 tolerant of copper salts by petri dish test, is the most sensitive to zinc chloride 

 and creosote. Poria microspora tolerates relatively greater concentrations 

 of all the compounds than any of the fungi tested. 



The four salts assayed can be easily dissohed in an agar medium in con- 

 centrations high enough to be toxic, but uniform dispersal of insoluble salts 



