78 



(c) Coconut. — March 20, a very thin pale-yellowish growth, not one one-hundredth 

 as much growth as in the check tube; the difference in color was not due to unlike 

 volumes; bulk for bulk on white paper the slime from the check tube was yellower 

 than that from the tube exposed to the vacuum. March 23, a thin growth covers 5 

 to 6 sq. cm.; it is yellow, but rather pale for this substratum. March 31, a bright- 

 yellow growth now covers most of the aerial portions of the cylinder. 



(d) Potato. — March 20, a distinct but feeble pale-yellow growth; about one-tenth 

 as much growth as in the check tube; the potato has not grayed; bulk for bulk 

 on white paper the slime from the check tube is yellower; compared as a whole the 

 culture in the check tube was a canary yellow; that from the vacuum was primrose 

 yellow. March 23, a thin growth covers 2 to 3 sq. cm.; it is yellow, but seems 

 unusually pale. 



Ps. campestris: 



(a) Carrot. — March 20, a very feeble growth; no check tube. March 23, a feeble, 

 wet growth which does not mask the color of the carrot. March 31, a feeble growth; 

 substratum not hidden. April 17, slime and fluid distinctly acid. 



(b) Beef broth. — March 20, clear; a very slight white precipitate closely resembling 

 that of Ps. hyacinthi; not over one-twentieth as much precipitate as in the corre- 

 sponding tube of Ps. stewarti. March 23, feebly clouded; March 31, well clouded. 



(c) Coconut. — March 20, a thin, pale-yellow growth over the whole aerial part of 

 the cylinder; about one-fiftieth as much growth as in the check tube, and paler yel- 

 low; the difference in color was also apparent when equal volumes of the slime 

 were placed side by side on white paper. March 23, 8 to 9 sq. cm. of rather pale- 

 yellow slime. March 31, a distinctly yellow growth over the whole exposed surface. 



(d) Potato. — March 20, the fluid is moderately cloudy and a thin, very pale-yellow 

 growth covers the whole aerial part of the potato; there is no precipitate, no gray- 

 ing of the potato, no thickening of the fluid or color in it; the check culture is 

 much yellower and contains fully 100 times as much growth; the check tube is wax 

 yellow; the other culture is as pale as j^rimrose yellow; side by side on white paper 

 in equal quantities the slime of the check tube was yellower. March 23, the entire 

 aerial part of the potato is covered with a yellow slime which also begins to fill the 

 water; it is still rather pale but begins to recover its color and vigor. March 31, a 

 copious typical growth. 



Ps. stewarti: 



(a) Carrot. — March 20, only the slightest trace of growth; no check tube. March 

 23, a slight growth, scarcely visible. ]March 31, fluid v/ell clouded; out of the water 

 there is a thin slime which does not hide the carrot. April 17, slime and fluid dis- 

 tinctly alkaline. 



(b) Beef broth. — March 20, fluid very feebly clouded; a pale-yellow precipitate, 

 6 mm. in breadth, i. e., more than in the corresponding tubes of Ps. Jii/acinfhl and Ps. 

 campestris; check tube twice as cloudy and with double the precipitate, which is 

 yellower; this organism seems to be able to get along with less oxygen than Ps. 

 hyacinthi or Ps. campestris. March 23, fluid feebly clouded; cloudier than when 

 taken out. March 31, well clouded. 



(c) Coconut. — March 20, a very thin, very pale-yellow growth; the check tube 

 contains several times as much growth and it is yellower; the one is bufr yellow, 

 the other is cream (Ridgway); removed from the tube and examined bulk for 

 bulk and side by side on white paper, the slime from the exposed tube was also dis- 

 tinctly paler. March 23, a very thin, buff-yellow growth covers 4 to 5 sq. cm; it is 

 paler than usual. March 31, there is now a thin, buff-yellow layer over the whole 

 exposed surface. 



(d) Potato. — March 20, a pale buff-yellow growth about one-third to one-half aa 

 abundant as in the check tube; i)otato not grayed, color only a little paler than 



