560 Bulletin 167 



dan (14). During- the incubation the alkali was partly neu- 

 tralized by the carbon dioxid absorbed from the air. The actual 

 reaction at the time the notes were taken was determined by 

 titrating control tubes with N/20 sodium hydroxid and phenol- 

 phthalein. The medium originally reacting at — 4.7 Fuller's 

 scale had an actual reaction of +2.4; that originally reacting at 

 — 12.4 had an actual reaction of — 6.1. Fluorescence had not 

 appeared in 26 days in the medium having an original reaction 

 of — 4.7, but in the medium having an original reaction of — 12.4 

 fluorescence was as marked as in agar cultures. The actual reac- 

 tion of the more alkaline medium at this time was -j-2.7 Fuller's 

 scale. Liquefaction has proceeded farther in this medium than 

 in the other, which now had a reaction of +4.4 Fuller's scale. 

 Gelatin liquefaction proceeded slowly and was completed in 

 45 days, at which time the fluid was rather clear and of an olive 

 green color. Considerable white flaky precipitate was thrown 

 down as liquefaction proceeded and a scum usually appeared. 

 There was a slight development in the line of puncture, liquefac- 

 tion occasionally appearing as a tunnel or as beaded spots along 

 the stab. 



Ps. mesenterial. — In 1 or 2 days the growth appeared as a 

 white line, filiform above and beaded below. The colony was 

 white with depressed center and irregularly dentate edge, occa- 

 sionally round with entire edge. Crateriform liquefaction usually 

 began in from 8 to 17 days, but was occasionally delayed until 

 about a month had elapsed. The liquefaction gradually became 

 stratiform and was practically completed in about 4 months. A 

 somewhat more rapid liquefaction and stronger fluorescence oc- 

 curred in alkaline gelatin ; however traces of green fluorescence 

 could be detected occasionally in gelatin reacting +10 Fuller's 

 scale. 



Strain CXIL — At the outset of these studies this organism 

 hist began gelatin liquefaction in about 10 days : at their close, 

 after an interval of two years, gelatin liquefaction constantly 

 appeared in 24 hours. In one to two days the growth was a 



