40 



(solidified). On the eighteenth day the whole substratum was browned 

 and this color was a much deeper brown than in the corresponding- 

 tube of Ps. hyacintM. On the tiftieth day the color was burnt umber, 

 and on the sixty-fourth day dark burnt umber. The slime was neu- 

 tral or slightly alkaline on the thirty-fourth day. and feebly alkaline 

 on the sixty-fourth day. The tissues were softened. 



On this substratum Ps. stewarti made a thin buff yellow, slightly 

 iridescent growth. On the seventh day there was one-fifth as much 

 growth as in corresponding tubes of Ps. hyaclntki and one-tenth as 

 nuich a.s in Ps. eampestris. Growth did not increase much after the 

 first or second week, and there was no browning or softening of the 

 substratum. The culture was alkaline on the thirty-fourth and sixty - 

 fourth days. After a time the water surrounding the turnip contained a 

 moderate amount' of buff" yellow precipitate, but it never became thick 

 or solid from excessive multiplication of the bacteria. 



Rutabaga. 



Test-tube cultures of this turnip (which had smooth glaucous leaves) 

 were prepared with distilled water in the ordinary way (see Potato). 

 The tests were made at the same time and in the same manner as on 

 the yellow globe turnip, and the results were much the same. 



With Ps. hyaemthi the growth was copious from the start, and not 

 only covered the cylinder, but filled the ffuid (solid). There was no 

 stain of the substratum until after the twenty-seventh day, but this 

 was covered by the bacterial growth so as not to be exposed an}'- 

 where directly to the air. On the fiftieth day the bacterial slime exhib- 

 ited a smooth, wet. dirty, brownish yellow surface. The upper part 

 of the substratum was now l^rowned. The slime was acid to neutral 

 litmus, leaving a distinct reddish color as it dried, and the cylinder was 

 softened so that it mashed easily with a glass rod. The fluid was still 

 plainly acid after adding 25 c. c. of water and stirring. On boiling- 

 only a trace of acid was given off' in the steam. On continuing the 

 boiling so that the fluid was reduced to 6 c. c. it was more strongly 

 acid, and the acidity became still more pronounced on reducing it to 3 

 c. c. The boiled fluid had a slightly bitter taste. There was a slow 

 evolution of gas and ]io white precipitate when this rather thick slime 

 was put into barium chloride water (acid). 



On thrs substratum Ps. campestris grew very promptly. By the 

 seventh day the fluid was grown solid and the cylinder in the air bore 

 on all parts a very copious, wet. shining, smooth, ^^ellow growth. At 

 this time there was already a slight stain of the substratum. This 

 stain became more pronounced and extended to the whole substratum 

 on or before the eighteenth day. This color (slime and substi^atum) 

 gradually deepened through raw umber (fiftieth day) to mummy brown 

 (sixty-fourth day). On the thirty-fourth and sixty-fourth days the 



