46 HISTORY AND CAUSE OF THE COCONUT BUD-EOT. 



a good one, extending for 7.5 centimeters above the inoculation hole 

 and 3 centimeters below it. As these inoculations were made with 

 a small injecting needle, the wound caused by the instrument itself 

 waa very slight. 



So many successful inoculations with bacterial cultures inevitabty 

 lead one to the conclusion that a rot in the heart tissues of the coco- 

 nut palm identical in every respect with the bud-rot is caused by 

 these bacterial organisms. That such a condition is caused by 

 mechanical injuries such as those of the inoculating instrument is 

 disproved by the check inoculations which produced absolutely no 

 rot at all. It has been suggested that the disease was carried by 

 means of the inoculating instrument to the inner tissues from affected 

 outer tissues. The possibility of this can not be denied. It is 

 impossible to obtain evidence of the fact that the bases of the leaves 

 and swords toward the interior are certainly free from disease. 

 From the general appearance of the tree one may judge all its parts 

 to be free or infected, but this is the best that can be done. However, 

 this objection does not lie against the hothouse experiments in 

 Washington, because the nuts were obtained from a disease-free 

 district. 



While this uncertainty may affect the probability of these inocu- 

 lations causing the rot in individual trees, yet in view of the fact 

 that the same organism as that injected into the tree has been 

 isolated from the artificially diseased tissues, the probability seems 

 greatly in favor of this particular organism, or else it suggests strongly 

 that if any bacteria were already present in the tissues and caused the 

 infection, they were of the same kind as those injected. Now that 

 these reisolated organisms have been inoculated into other trees 

 and have induced typical soft rots, from which the same organisms 

 have been reisolated, proof seems complete that at least a certain 

 kind of bacteria, namely the kind used in the successful inoculations 

 just described, does cause the diseased condition of the coconut 

 palm known as bud-rot. 



No experiments have been carried on to prove that this is the only 

 organism causing the bud-rot. The fact that cultures of apparently 

 different organisms did produce decayed tissues certainly suggests 

 that other organisms than the one isolated may produce the same 

 effect. At the same time slight differences in the appearance of 

 colonies on agar can not be regarded as specific. The question of 

 the power of other organisms to produce the same appearance is an 

 interesting one and undoubtedly will arise again with further work. 

 It seems sufficient for the present (1) to have proved that this con- 

 dition is due to a bacterial infection and (2) to have isolated a par- 

 ticular organism which is capable of producing the disease. 



228 



