CULTURAL CHARACTERS OF THE DAISY ORGANISM. 123 



to 0° C. before inoculating. The tubes were thrust far down into 

 finely pulverized ice in a wine cooler which was set into the ice box 

 close to large cakes of ice. Ice was added to the cooler night and 

 morning after siphoning off the accumulated water. The tempera- 

 ture held constantly at 0° to 0.2° C. It was never above +0.2° C. 

 The experiment was begun Alarch 3, 1908. On March 7 there was a 

 decided growth in the bouillon tubes but none on the agar. On 

 Afarch 9 a very slight growth was detected on the agar. On March 

 17, when the experiment was discontinued, the growth in the bouil- 

 lon, although not heavy, was sufficient to show the usual character- 

 istics. It was all at the bottom of the tube, none on the surface. 

 There was enough growth on the agar to be visible, but it was slight. 

 The bacteria in the bouillon were examined microscopically and 

 many involution forms were found and drawings were made (fig. 2). 

 Plates were poured from the bouillon and the daisy organism obtained 

 in })ure culture. 



In order to obtain a still lower temperature, salt was mixed with 

 the ice in a quinine can and the can was placed in a galvanized-iron 

 bucket 10 inches in diameter. The bottom of the can, as well as of the 

 bucket, was perforated to allow the water to escape. Both can and 

 bucket were iced twice daily, using 4 tablespoonfuls of salt at each 

 icing. The tubes were inoculated as before, and placed in the ice- 

 salt mixture in which the thermometer was also placed. The 

 bucket containing the ice and the quinine can with its contents was 

 placed in the ice compartment of the ice box. Witliin a few minutes 

 after the tubes were placed in the ice-salt mixture the contents had 

 solidified and remained solid during the 2 weeks that the experi- 

 ment was continued. The temperature varied from 0° to —14° C, 

 but was never higher than 0° C. during the 2 weeks. At the expira- 

 tion of this time the cultures were removed to room temperature 

 where the beef broth quickly melted and was found to contain a 

 distinct characteristic stringy growth, l:)ut only very slight. No 

 growth was visible on the slant agar tubes. 



EFFECT OF DRYING. 



TJie daisy organism is 'killed readily by drying. An experiment 

 made in April, 1910 (temperature 25° C), gave the following result: 

 Tiny drops of a bouillon culture 5 days old were spread on 25 clean, 

 sterile, small cover glasses and set away on a shelf in the culture room 

 (in diffused north light) in a covered, sterile Petri dish. The covers 

 were then taken up by means of sterile forceps and dropped into 

 tubes of sterile bouillon, one into each tube, with the following results: 



Alive: Number of days dried, 1, 3, 7, 12. 

 Dead; Number of days dried, 2, 5, 6, 8, 9, 10, 13, 14, 15, 16. 

 213 



