- 35 



Table V. 



Rice flour, which gave luxuriant growth when used with bouillon 

 by Schneider (19) and P e t r o w (58), gives good pigment, but rather 

 a thin dry layer, when bouillon is omitted. 



The similarity between B. ruber balticus and B. kiliensis 

 was brought out by their development on starch and water. On 

 the other hand B. prodigiosus, B. ruber miquel, and 

 B. rutilus scarcely developed at all on cooked starch, but with the 

 addition of 1 % peptone gave a luxuriant growth. B. rutilus was 

 peculiar here in its absence of pigment, while B. amyloruber for 

 the first time produced, in addition to its usual vivid dark red color, 

 a distinct green metallic luster. The development of this organism 

 was evidently at its height of luxuriance on the starch-peptone 

 medium. Considerable liquefaction of the solid starch also took 

 place, an evidence of the production of a diastatic ferment by 

 B. amyloruber. After two weeks the semi-solid mass on this 

 plate was rubbed up in distilled water, filtered germ free and tested. 

 12 ccm peptonized 5 ccm of 10 % gelatin and water in two hours 

 at 37 C. A half inch cube of 10 % cooked starch was not liquefied 

 by the filtrate in 24 hours at 37 C, and I am unable to adduce 

 any evidence, other than that of the first observation, for the presence 

 of diastase. Fermi (22), and G o r i n i (41) report negative results as 

 regards diastatic ferments from B. prodigiosus and "B. ruber". 



c. Growth and pigment in non-proteid media. 



The value of the above experiments as to the affect of sugars 

 could only be tested by their repetition with non-proteid media, 

 where all the elements which go to make up the nutritive supply of 

 the organisms are definitely known. The only investigations of this 

 sort hitherto undertaken for red chromogenic forms have been upon 

 B. prodigiosus and B. kiliensis. Those upon the latter orga- 

 nism, by Laurent (57), were carried out mainly to test the effect 

 of acid in the medium, and led Laurent to the conclusion that an 

 alkaline reaction was most favorable to growth and pigmentation. But 



