34 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 10 



except those in which B. coli was planted. Incidentally, it may 

 be stated that the strain of B. coli used gave rise to a stronger 

 color reaction in the YYitte peptone solution than in the "Bacto" 

 peptone solution. 



Heating at 70° (X for a few minutes did not bring out the 

 slightest trace of pink coloration in any of the cultures inoc- 

 ulated with strains of the blackleg organism. Cultures kept 

 for 2 months wore also tested, and negative results were ob- 

 tained as before. In these cultures a yellowish or faint brown 

 coloration was noticed after adding the test solution. Upon 

 looking across the surface of the liquid against a dark back- 

 ground, the suggestion of a very pale wine coloration was ob- 

 tained which in thi 3 absence of the positive test color might be 

 mistaken for indol production. Possibly some of the authors 

 who have reported tt mt the blackleg bacillus produced indol were 

 led astray by the ap, oearance of similar color reactions in their 



test 

 cepting such 



Repea ted warnings have been 



indication of indol. When 



compared with the ph ik color appearing in cultures of 



tested for indol, one is not likely to make an erroneous inter- 

 pretation. 



Nitrites from nitrates.^ Nitrates reduced. 



Strain No. 191 was the onl Y on e that did not reduce nitrates 

 to nitrites. The starch-Kl '-sulphuric-acid test recommended by 

 bmith ('05) was employed. 



Ammonia production.— M^ irate - 



Standard nitrate broth w% used as a culture medium. Du- 

 plicate tubes were inoculated,, © ne of which was sealed with paraf- 

 fin. When this was tested mt the end of the tenth day, using 



Nessle 



cefo ration appeared in all tubes 



cept controls. The color was sii* " htl v deeper in the sealed tubes. 



Fermentation.— Acid and .small w >lu mes of gas from dextrose, lac- 

 tose sucrose, maltose, and mannitc*. No acid or &as from glycerin, 

 aextnn, and potato starch. Moderaft ■ S row th in closed Tm of fer- 

 mentation tubes, from which dissctfi ed °W n is d ™ « off, in 



fpphiT ee °L£ e ? tT0Be > lactose > morose i nalt0S ''- No 8rovvth at first ' 

 lit* n Wth later in elose <* arm l!n fo ' simi,ar conditions, in pres- 



ch. Q 



no h;Lr s r„ n f ss? ir rf of ~ T0Se ' laetose ' and malt08e - 





