27 



THE KILLING OF BOTRYTIS SPORES BY PHENOLi 



By J. HENDERSON SMITH, M.B., Ch.B. 



{From the Deparlnient of Mycology, Rofhamsted Exferimental Station.) 



(With 11 Text-figures,) 



Seveeal workers have studied the manner in which bacteria are killed 

 when submitted to the action of poisons: their conclusions are referred 

 to later. One might expect that in the case of fungi the findings would 

 be the same, but little accurate and detailed information is available, 

 and as there is still a great deal of uncertainty, partly as to the facts, 

 and still more as to their interpretation, in the kilhng of bacteria, it 

 seemed possible some further hght might be obtained by a study of the 

 problem, using fungi as the test object. 



The organism selected was Botrytis cinerea, the strain used being 

 the one described by Brierley(i). From a single spore of this strain 

 cultures were obtained on Czapek's medium, and in all the experiments 

 detailed here Czapek's has been the only medium used. 



Method. 



The method adopted was as follows. The spores were sown on 

 Czapek-agar slopes, which were kept at room temperature in a subdued 

 light till used. From these a suspension of spores was prepared of the 

 desired density in distilled water. In removing the spores care was 

 taken not to touch the subjacent medium and to obtain a suspension 

 as free as possible from hyphae. This was done by laying Hghtly on the 

 tops of the conidiophores a platinum loop filled with distilled water: 

 the spores adhere to the film of water on the loop and are transferred 

 to a tube of water and washed ofE. By repeated apphcation of the loop 

 a suspension is obtained of practically pure spores. To a measured 

 volume of the suspension, previously brought to the desired temperature, 

 w^as added an equal volume (also previously warmed) of the toxic agent 

 to be examined, in such strength that the final mixture was of the 

 desired concentration. The mixture was maintained in a water-bath at 



1 A grant in aid of publication has been received for this communication. 



