109 



perature 8.2^ C), there had been some further g-rowth. On June 4, 9 

 a. m. (temperature 8.5° C), there Avas a distinct increase of growth 

 over Avhat was present '24: hours earlier. One of the two tubes was 

 now removed to room temperatures of 25° to 26° C. During the next 

 2(> hours the growth in this tube doubled. During the same period 

 there was a slight growth in the other tube (temperature 8.5° C). 

 At this time, in this tube, a ])right yellow growth covered umw than 

 1 s([. cm. of the surface where 5 days before (after the shaking) no 

 growth whatever was visible. All of this growth took place between 

 7.-i° and 9° C, the temperature most of the time during the 5 da3^s 

 ranging between 7.5° and 8.5° C. 



(4:) Four tubes of strongly alkaline beef broth (stock 882 neutral to 

 phenolphthalein) Avere each inoculated Avith a 3 mm. loop from a Avell- 

 clouded beef broth culture 8 days old. One of these tubes Avas held 

 at room temperatures of 20° to 25° C. This culture Avas moderately 

 clouded on the third day and passed through a normal growth. The 

 other 8 tubes Avere placed in the ice chest for 18 days at 2.8° to 4.5° C. 

 (mostly 3° to 1° C), during the Avhole of which time they remained 

 perfectly clear. On then removing them to room temperatures they 

 clouded in 16 hours at 21°-28° C. The rapidity Avith Avhich they 

 clouded Avhen remoNed from the ice box suggests that the bacteria 

 grcAV slightly at times while exposed to the low temperature. 



The minimum temperature of Ps. ca/z/pestri-'^; is not known. It lies 

 beloAV 7° C. The minimum temperature of Ps. steivarti is not knoAvn 

 exactly, but it is believed to be a degree or tAvo higher than that of 

 Ps. hyuc'nithi for the following reason: Tubes of Pa. stewartl Avere 

 exposed in the ice box at 2.8° to 4.5° C, along with those of the 

 hA'acinth germ. There was no clouding in 18 days, and on removing 

 to room temperatures the tubes were not clouded until the third or 

 fourth da}', and then only feebl}^ The check tubes clouded on the 

 second and third days. The fluids used were Uschinsky's solution and 

 an alkaline beef broth (stock 382). Each tube was inoculated with 

 one 8-millimeter loop from a young fluid culture (3 daj^s old). The 

 date of clouding on removal indicates clearh^ that, contrary to the case 

 of Px. Jiyacinthl.^ there had been no growth whatcA^er during the 18 

 days' sojourn of the tubes in the ice chest. 



FOKAIATION OF AC^IDS. 



With exception of th(^ production of a small amount of acid from 

 ethyl alcohol (probably acetic acid), the formation of acids by Pa. 

 hyacinthl is rather o])scure, in spite of all the attention I have given 

 to it. At times, especially when small ([iiantities of the carbohj^drate 

 were used, no acid was detected from the groAvth of this organism in 

 the presence of sugars. Even Avhen large quantities of the A^arious 

 sugars Avere used there Avas no prompt change from alkaline or neutral 



