1906] BROOKS—TEMPERATURE AND TOXIC ACTION 363 
twenty-four hours and notes taken of percentage of germination, 
length of germ tube, fruiting, and any peculiarities in germination 
or development. More frequent observations would have been of 
interest, but they were not made on account of the increased source 
of error that would have been thus introduced. Any sources of error 
that were not otherwise provided for were guarded against by always 
making duplicate cultures. The experiments with the three chemi- 
cals were always made at different times, and as control cultures 
were made in every case, the growth of each fungus in a nutrient 
medium at a particular temperature was tested six times. 
The vitality of spores that had been subjected to the action of an 
inhibiting toxic agent was tested by transfer to a nutrient non-toxic 
medium, An attempt was made to accomplish this transfer by 
Temoving the drop of the toxic solution with sterilized filter paper and 
replacing it by a drop of beet decoction. This method left some 
part of the former solution as well as any precipitate that had been 
formed adhering to the cover glass, and was therefore adandoned. 
All transfers that are concerned in the following data were made by 
means of a sterilized platinum needle. The spores were in every 
case transferred to a drop of beet decoction on a clean cover glass. 
The medium used in the bottom of the cells was in this, as well as 
in all other cases, the same as that of the hanging drop. It is quite 
evident that the above method of transferring did not prevent a 
small amount of the toxic solution being carried into the new drop 
by the spores and the needle, but the results obtained indicated that 
this small per cent. of the toxic agent either served as a very slight 
stimulus to germination and growth or exerted no appreciable 
influence, 
Early in the work it was seen that results obtained from the 
exposure of the fungous spores to the toxic agent must be considered 
entirely apart from the data secured in cases where the mycelium 
was acted upon by the toxic solution. Therefore, when a particular 
toxic solution gave no germination at one temperature, but did at 
others, the ungerminated spores were in no case transferred ; es 
transfers were made only with those solutions that gave no germina- 
tion even at the optimum temperature at the end of the given time. 
By a series of preliminary experiments strengths of toxic solution 
