152 CONTRIBUTIONS TO OUR KNOWLEDGE OF SOIL-FERTILITY, XVI., 



become decayed by the l'2th It appeared advisable, therefore, 

 to test the solutions, from time to time, to see the influence of 

 the time-fa(;tor. Tliis was done in the following experiment, in 

 which Bac. T.P.2 was used at 16° to 1 8\ 

 Experiment xi. 



" The numbers in these are irregular, largely owing to the counts being 

 low. 



During the filtration of the infusions through the porcelain, it 

 was noted that, in the dextrose-media, a considerable amount of 

 slime had been formed. Attention was not called to this in the 

 three days' culture, but, in the five and eleven days' culture, the 

 slime was pronounced. It is clear from the results that the 

 organism had produced a certain amount of toxin about the 

 sixth day in the simple hay-infusion, and that it had largely 

 disappeared by the eleventh day. The ratio of growth, which 

 is a rough index of the approximate amounts of nutrients in the 

 extract, declined as time went on, and so did the effect of boiling 

 the solution. In the hay- and dextrose-solutions, boiling showed 

 a steady increase of nutrient produced as the age of the culture 

 increased, while, without dextrose, the reverse was the case. 



The organism T.P.2 was originally obtained upon an agar-plate 

 which had been seeded with a suspension of soil-bacteria. It 

 was conspicuous in producing a zone across which neither moulds 

 nor spreading bacteria would go. The single colony upon puri- 

 fication was found to consist of two closely allied forms pro- 



