37 



The slinio was feebly alkaline on tlie thirty-fourth and sixty- fourth 

 daj^s whit'hi^'ei- niodiuni was used. 



AVjiite Turnip. 



Slices from the roots of smooth, green-leaved (nong'laucous), flat- 

 bottomed, edible, white turnips were prepared in the same way as the 

 potato cylinders. 



The hyacinth organism grew well on this substratum and without any 

 marked retardation. On the third day, at 21'^ to 23'^ C. , the growth was 

 very feeble in comparison with that of Ps. cmrq^estris or Ps. plumeoli. 

 On the seventh day, at 20*^ to 23°, the growth was copious over the whole 

 of the exposed part of the cylinder and the fluid was ver}' cloudy, but 

 there w^as little or no precipitate. On the twenty-second day growth 

 was copious in the air and also in the upper part of the water, i. e., 

 there was a better growth than in corresponding tubes of potato. 

 After 54: days there was still a copious growth. 



The surface of the slime was smooth and wet-shining, even in old 

 cidtures (54 da3\s). 



After 7 da3's at room temperatures the color in one tube was pale 

 3^ellow, except the scanty precipitate, which was canary yellow. After 

 22 daj^s the same culture was pale 3'ellow. In another tube, on the 

 seventh da}', the color was unlike any in Ridgwav's book, but approxi- 

 mated his Naples yellow (VI-IS). This slime was plainly yellower 

 than the equall}' copious growth in a corresponding tube of P><. caiii- 

 ■peKtriK. At the end of 25 days the slime in the upper part of the tube 

 against the glass had developed a pale reddish-yellow color, quite in 

 contrast with the color of a corresponding tube of Px. p^iaseoll. There 

 was also the merest trace of this color in the first cultures on radish. 

 After 50 da3's at room temperatures the slime in one tube was "dirt}'^ 

 yellow," while in another it was "pale 3'ellow," i. e., much paler than 

 in a culture of the same age on coconut. In mass, on white paper, 

 this pale yellow slime was between Ridgwa3''s ])uff 3^ellow and maize 

 yellow (VI-19 and 21). 



After 54 da3'^s, at room temperatures, the slime snowed no alkaline 

 reaction, but was plainly acid to neutral litnuis paper (only one tube 

 tested). This red r(MU'tion was appar(;nt at once and l)ecamft stronger 

 as the paper dried. 



A brown stain slowly developed in the substratum, ))eing clearly 

 visi))lc onl3' after 2 or 3 weeks. On the twent3"-second day and the 

 thirt3'-eighth da3' the substratum was not browned as much as in corre- 

 sponding cultures on 3'ellow turnips. On the thirty-eighth da}' the color 

 in one tu))e approximated Ridgwa3''s russet. In another culture of 

 the same age the ))rown was paler, approximating his tawny olive. 

 On the foi-ty-ninth da3' the substratum was darker than on the nine- 

 teenth, and was several shades daiker than in a corresponding tube of 



