114 HISTORY AND CAUSE OF THE COCONUT BUD-EOT. 



COHN S SOLUTION. 



Cultures 1 to 6 and Bacillus coli show only a very slight indication 

 of growth, with the exception of No. 5, which in one experiment 

 became well clouded. In a repetition by Mss Lucia McCulloch, an 

 associate worker, the same restilts were obtained. The six coconut 

 strains and four Bacillus coli strains were inoculated from agar slant 

 cultures three days old, using one 1-mm. loop. The tubes w^ere 

 incubated at 33° C. No growth occurred in any except coconut No. 

 5, which formed a heavy pellicle and numerous crystals. 



POTATO AGAR. 



Excellent widespread, wet-shining, wlxite growth ^nth raised irreg- 

 ular margins in all the tubes within 48 hours. 



CARROT AGAR. 



Growth on tubes of carrot agar is thin, wet shining, white, but 

 very restricted, never extending over the surface of the medium. 



LITMUS-LACTOSE AGAR.' 



Growth on htmus-agar slant tubes is barely perceptible, thin, trans- 

 parent, and spreads along the streak. Occasionally it develops into 

 small colonies, in which case it reddens the htmus. 



On plates both Bacillus coli and the coconut organism form small 

 colonies which redden the litmus and are semitransparent and 

 zooglcea-like. 



OXALIC-ACID AGAR. 



Growth on agar containing 0.2 per cent oxalic acid is similar to 

 that on htmus-lactose agar, being very shght. 



MERCURIC CHLORID. 



Solutions of beef bouillon containing different percentages of mercuric 

 chlorid were made up for the purpose of ascertaining how strong a 

 solution this organism was able to withstand. In one experiment 

 none of the cultures were able to survive in a solution containing 

 mercuric clilorid as strong as 1 to 3,000. In another experiment the 

 cultures became heavily clouded when the tubes contained mercuric 

 chlorid in the proportion of 1 to 1,000, as well as in weaker propor- 

 tions up to 1 to 7,000. 



Mss Lucia McCulloch made additional tests as follows: A flask con- 

 taining 250 c. c. of mercuric clilorid water (1 to 1,000) was inoculated 

 with one 1-mm. loop of the cloudy water in the V of an agar slant 

 culture (48 hours old) of coconut No. 5. After 1 minute of vigor- 

 ous shaking two plates were poured. At the end of 3, 5, and 10 



' For description of the use of litmus-lactose agar or gelatin, see Wurtz's "Method for the Differentiation 

 of Bacillus Typhi from Bacillus Coli," Technology Quarterly, vol. 6, 1893, pp. 241-251. 

 228 



