loo Journal of Agricultural Research voi. iv, no. i 



Gelatin is liquefied, the line of puncture is filiform, and the growth of 

 the organism takes place at the surface of the culture. 



Dunham's solution shows more or less clouding, the heaviest growth 

 taking place in the open end of the tube, where a flocculent growth is 

 noted at the surface. No traces of indol were noted. 



This organism produces no gas in the presence of Dunham's solution 

 in combination with dextrose, lactose, or mannit. The organism grows 

 well in all these combinations, especially at the open end of the tube, 

 where a flocculent growth is produced. Dextrose appears to favor the 

 development of this organism particularly, as a heavy, flocculent growth 

 is formed throughout the entire tube. It grows but sparingly in Ushin- 

 sky's solution, and in starch-nitrate solution does not reduce the nitrate. 

 The organism grows best under aerobic conditions. 



The organism stains readily with carbol fuchsin, and flagella have been 

 demonstrated by means of the methods of Van Ermengem and Dr. Hugh 

 Williams. (See PI. IX, fig. 2.) 



Much confusion and uncertainty seem to exist in the minds of Citrus 

 growers and others in regard to the identification of the true Citrus canker. 

 Many specimens supposed- to be infected with canker which have been 

 sent for identification have been found to be injured by fungi or some 

 other cause. A most careful and detailed comparative study of Citrus 

 canker and other diseases resembling it must be made in order to clear 

 up the canker problem and reduce the necessity of frequent bacteriolog- 

 ical diagnoses. 



Although this paper gives only a very brief account of the etiology 

 of the Citrus canker and many important facts in the life history 

 of the causal organism remain to be determined, the immediate publi- 

 cation of this preliminary report is considered necessary on account of 

 the great economic significance of this disease, which up to the present 

 has been supposed to be due to a fungous parasite. Because the methods 

 of control for bacterial diseases diff"er quite radically from those employed 

 for fungous diseases it is hoped that the presentation of this report at 

 this early stage in the investigation will lead to a more adequate under- 

 standing of the precautions which may be essential in an effective cam- 

 paign of eradication. 



