28 abstracts: phytopathology 



of ammonium oxalate being injected into a seedling at the same time as 

 a check. Eighteen days after the injection the material was collected, 

 plates were poured, and in five days pink colonies typical of both the 

 coconut organism and of B. coli were formed on their respective plates. 

 Along with the other inoculations just described a second injection of 

 B. coli (derived from animals) was made into a coconut seedling, and also 

 another solution of ammonium oxalate. After 47 days there was a good 

 typical soft rot in the seedling inoculated with B. coli, but there was no 

 characteristic effect from the ammonium oxalate. From this material 

 B. coli was isolated, both by the author and by Miss McCulloch. Six 

 experiments in all were conducted in which many inoculations were made 

 with pure cultures of Bacillus coli from animals, a good soft rot being 

 produced in the heart tissues of the coconut crown in most cases — a rot 

 similar to that produced by the inoculations with the coconut organisms 

 which were made at the same time. A full table is given, summarizing 

 the characters of the coconut organisms and of B. coli, in which but 

 slight variations are noted. In summing up the comparative study of 

 these organisms, Mr. Johnston says: 



In the course of such an extended study on a disease as this has been 

 there naturally occur certain results some of which tend to weaken the 

 case and others to strengthen it. The many successful inoculations and 

 the similarity of the cultures injected and isolated, together with the 

 similarity of many other cultures isolated from diseased coconut mate- 

 rial by the writer and earlier by Dr. Smith all tend to strengthen the case. 

 On the other hand, successful inoculations by the writer with cultures 

 of variable appearance rather tend to weaken the argument. These 

 results may be explained by the supposition that other organisms than 

 Bacillus coli also produce the bud-rot, or that what passes for Bacillus 

 coli includes a group of closely related but not identical organisms. 



After the above experiments were conducted it was decided to search 

 directly in the diseased tissues for B. coli. Material was obtained from 

 Baracoa, Cuba, transfers being made, under clean conditions, to tubes 

 of Dolt's synthetic medium. Platings were made in Washington, and 

 B. coli was present as indicated by the tests. Subsequently more mate- 

 rial was obtained with a similar result, Bacillus coli being isolated 1 6 days 

 after the material was collected. 



Comparison of the bud-rot caused by Bacillus coli with several diseases 

 of the coconut palm ascribed in literature to other causes indicates that 

 several of these diseases are identical with bud-rot. It is not known at 

 present that this bud-rot occurs on other palms than the coconut, but 

 it probably does. 



