Bui. 227, U. S. Dept. of Agriculture. 



Plate II. 



Toxicity Studies: Petri-Dish Cultures of Fomes annosus and Fomes pinicola.-I. 



FlGS 10 and 11.— F. annosus on dillcrent concentrations of coal-tar creosote, Fraction I, after 5 

 weeks: 10, on 0.2(5 per cent; 11, on 0.3 per cent. Figs. 12 and 13.— F. pinicola on diflerenl 

 concentrations of coal-tar creosote, Fraction II, after 5 1 -\ weeks: 12, On 0.125 per cent; 13. on 



0.15 per cent. Figs. 14 to 19.— F. pinicola on different concentrations of coal tar cr te 



Fraction I\< , after 9 weeks: 14, Check; 15, on 0.02S per cent; lti. on 0.05 percent; 17, on 0.075 

 per cent; is. on o.i per ccni; p.i. on 0.125 per cent. Figs. 20 to 23.— F. annosus on diflerenl 

 concentrations of coal-tar creosote, Fract ion V, after 7 weeks: 20, Check: 21. on 0.1 per ce 

 22, on 0.5 per cent; 23, on 1 per cent. Fig. 24.—/'. pinicola on 1 per cent concentration oi CO 

 tar creosote, Fraction V, after G weeks. 



