38 HISTORY AND CAUSE OF THE COCONUT BUD-EOT. 



The trunk of the coconut tree is an almost uniform mass of fibers . 

 and fundamental tissue from the roots to the croAvn, and is a hard, 

 woody material. The roots are veiy numerous and radiate hori- 

 zontally in all directions from the tree, extending practically as far 

 as the leaves of the crown. The roots are almost uniform in size, 

 about 1 centimeter in diameter. 



The accompanying figures 8 and 9 are intended to show the rela- 

 tion of the different parts in cross section and in longitudinal section. 

 It is difficult, or impossible, to show all parts in their proportionate 

 sizes, but their relative position is more important, and it is believed 

 that this may be clearly seen. The cross section is such as would 

 appear if made through the line BB of the longitudinal section after 

 the removal of the external leaves. 



FIELD STUDIES OF THE DISEASE. 

 INFECTION STUDIES. 



To determine the infectiousness of the disease was the first problem. 

 That bud-rot was communicable from tree to tree was accepted by 

 some, but ignored or disbelieved by others. By many it has been 

 thought due to something in the soil or to the climatic conditions, and 

 various applications have been made to the base of the tree in the 

 hope of curing it. Insects eating the roots and working in the trunk 

 or in the cro'WTi have also been considered as causes. It has likewise 

 been claimed that a mechanical injur}^, such as a bullet piercing the 

 tender heart tissues, would produce a rot of the crown. It is safe to 

 say that most of the reasons given as to the causes were based on 

 inaccurate or incomplete observations, together with a lack of any 

 experiments to substantiate them. The rapid spread of the disease 

 in itself seems good evidence of its infectious nature, for it does not 

 stop in one valley or one grove, but frequently spreads over a hillside 

 and into the next valley, always beginning in a small way and from 

 that spreading sporadically over the entire grove. If the disease were 

 due to soil or to climatic changes, many or all of the trees would show 

 signs of the rot about the same time. It could hardly be supposed 

 that this might be accounted for by variation in individual resistance, 

 since in the end most or all of the trees contract the disease. 



Assuming the trouble to be infectious, it has been a mooted 

 question as to whether fungi or bacteria were the cause of it. 

 Prior to 1887 Dr. Ramos, of Havana, maintained that a fungus 

 iUredo coccivoro) was the cause. This has been upheld by many, 

 but by others — notably bacteriologists — it has been disputed a 

 priori on the ground that fungi seldom cause a putrid fermentation 

 such as is to be found in the crown of the diseased coconut tree, while 



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