40 



Killing of Botrytis Spores by Phenol 



and the disturbing influences difficult to eliminate. It seems probable, 

 however, that the individual spore does not remove one-hundredth part 

 of its own weight of phenol. If this is so, one might expect that a solution 

 containing by weight several hundred times the amount of phenol taken 

 by the spores would contain a practically infinite amount of phenol 

 relatively to the spores, and that any alteration of the phenol-spore 

 ratio would have a scarcely appreciable effect on the time of killing. But 

 this, as we have seen, is not in fact the case. 



Experiments ivith Young Spores. We have seen that for technical 

 reasons it was not possible to obtain a logarithmic survivor curve when 

 using adult spores, and that the use of low temperatures did not help. 

 It is, however, possible to approach the question in another way by 

 using spores of a different character. At room temperature on Czapek- 

 agar Botrytis spores are first clearly visible to the naked eye on the 

 5th to the 6th day after inoculation of the tube. When first formed they 

 are in the mass of a pale grey colour instead of the dark mouse colour 

 they assume later. They are at this period already "ripe," since they 

 are fully formed and germinate freely, but they are less resistant, as 

 may be seen on a comparison of the times required for kilhng in the 

 following tables with those already given, I accordingly carried out a 

 series of experiments with young spores removed from the tubes soon 

 after they were clearly formed. These are detailed in Tables XVII-XIX, 

 and the graphs drawn in Figs. 5 and 6. 



Table XVII. 22,3,20, 9 day Table XVIII, 1.4.20. 7 day 

 spores. Phenol 0-7 per cent. Both spores. Phenol 0-7 per cent. 

 seriesfromsamesuspension,26-3°. 26-2°. 



Time in 40,000 in 



Value 



