34 BULLETIN 1053, U. S. DEPARTMENT OF AGRICULTURE. 



trabea showed little or no retarding effect in percentage of germina- 

 tion at 44° C. 



A single test upon the effect of cold on the oidia of Lenzites 

 sepiaria and chlamydospores of Trametes serlalis was made. Slides 



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Fig. 3. — Effect of temperature upon the germination of the oidia of Lenzites sepiaria and 

 L. trabea and of the chlamydospores of Trametes serlalis. A, Effect of temperature 

 upon the percentage of germination, showing the maximum percentage obtained, regard 1 

 less of the time element ; B, percentage of germination in 20 hours ; C, rate of growth 

 of the thalli in 20 hours (shown in microns). 



were left out of doors over night when the temperature varied from 

 —19° C. to —23° C. (—3° to —10° F.). The next morning germina- 

 tion tests were made, and it was found that the oidia had not been 



