nutrip:nt media. 21 



Ditn/iaw's solution. — Several tubes of Dunluim's solution were inoc- 

 ulated with a 1-min. loop of a 24-hour-okl culture of the calhi rot 

 oroanisni in beef broth. In twentv-four hours at 20 C a faint rloudi- 

 ness was perceptible. Tliis increased slijrlitly from da\' to day for 

 about six days. The temperature durino- this time ranged from 18^ 

 to 25'^ C. The cloudiness then seemed to remain practic:dly constant 

 for about one week. A deposit was jrradually formed, and in one 

 month from the time of inoculation the solution l)ecame almost clear, 

 showinj^ that the oroanism had ceased .to live. The deposit formed 

 was al)out 1 mm. in depth and had a faint })rownish tin^e. 



DunhaiiiS solution., vuth ((cidfuchsi)i. — This solution was inoculated 

 the same as above. At the end of one week the solution in the inocu- 

 lated tubes was liohter colored than in the control tul)es. At the end 

 of one month after inoculation the bleaching seemed to have ceased. 

 The organisms were nearly all dead, as indicated l)y the fact that the 

 liquid was practically clear. While the solution in the inoculated 

 tubes was somewhat i)inkish in color, it was decidedly lighter than the 

 solution in the control tubes. The deposit was the same in color and 

 in (piantity as in the Dunham solution given above. 



Dunhani's solution., uiith indiijo-carinine. — ^Sterile tul)es of this solu- 

 tion were inoculated in the same manner as the Dunham's solution. 

 In two days the inoculated tul)es were slightly blue when seen by 

 reflected light. This color deepened from day to day for a])out one 

 week, after which time it remained practically constant. The inocu- 

 lated tubes were only slightly clouded at the end of two weeks, and a 

 small quantity of deposit with a faint brownish tinge had formed in 

 the bottom of the inoculated tubes. 



Peptone solution., ivith rosolic acid. — A nutrient solution containing 

 rosolic acid was inoculated with a 1-mm. loop from a 24-hour-old beef- 

 broth culture, and at the end of one week the solution had a milky 

 appearance, due to the presence of a large number of organisms. Ten 

 da3's later there was no change, except the formation of a small 

 amount of white deposit. At the end of thirty days after inoculation 

 the tubes were still slightly clouded, but no change in color was 

 apparent. The deposit had increased and had assumed a faint brown- 

 ish tinge. 



Dunhani's solution., vnth methylene hlue. — Two preparations con- 

 taining peptone and methylene blue were used. Thelirst consisted of 

 a 1 per cent solution of Witte's peptone, to which was added 0.5 per 

 cent c. p. sodium chlorid and 3 c. c. of a 1 per cent aqueous solution 

 of meth3dene blue. SterUe tubes of the solution were inoculated 

 with puie 24-hour-old beef -broth cultures of the calla-rot germ. 

 These inoculated tubes were compared with the controls for two 

 months subsequent to inoculation, but no change in color could be 

 detected. 



