FIELD STUDIES OF THE DISEASE. 



45 



No. 501 was examined after 13 days; it showed an excellent decay for a distance 

 i>f 60 centimeters above the inoculation and a considerable distance below it. 



No. 504 was examined after 14 days, when it showed a good soft rot extending 4 

 centimeters about the inoculation hole. 



Three other inoculated trees, Nos. 601, 602, and 603, were not examined. 



Following the examination of these inoculated trees, plates were 

 poured from the diseased tissue, and an attempt was made t<) isolate 

 the organism present in the diseased parts. By comparing the 

 predommant organism isolated in each case from these trees with 

 the organism inoculated into the trees, it was found in a good many 

 cases that several of these organisms seemed to be identical. This 

 fact lent encouragement to the use of some of these isolated organ- 

 isms for reinoculation into another series of trees. Unfortunately, 

 it was not possible at this time to carry on the work in Cuba, so that 

 inoculations were made into seedling coconuts in the greenhouse at 

 Washington. These coconuts were not by any means desirable for 

 this purpose, being decidedly stunted in their growth, and in con- 

 sequence their tissues appeared to be drier and more woody than is 

 natural to the tree. It was rather to be expected that greater 

 difficulty would be encountered in producing the rot in these seed- 

 ling coconuts than if the inoculations were made in good healthy 

 trees. Table IV gives the results of these inoculations. 



Table IV. — Greenhouse inoculations of coconut trees, September 24 to 29, 1909. 



Source of culture. 

 Tree No. 



503 (N series only) . 

 506 



505, 

 508. 



Character of 

 colony. 



Thin, white, 



irregular. 

 do 



.do 

 .do. 



Inocu- 

 lated 

 into 

 tree No. 



503 a 

 506 a 



505 a 

 508 o 



Date of 

 inocula- 

 tion. • 



Sept 24 

 Sept 29 



...do 



Sept. 24 



Date of 

 of exam- 

 ination. 



Oct. 27 

 ..do.... 



...do 



Oct. 16 



Results. 



A small, rotted area and a large 

 water-soaked area. 



Water-soaked area for a distance of 

 1 centimeter from Inoculation 

 hole. 



Excellent brown, water-soaked con- 

 dition. 



Rot extended about 7.5 centimeters 

 above hole and 2.5 centimeters be- 

 low it in inner tissues; typical 

 soft, white rot in inner tissues. ■ 



The results of the inoculations, shown in Table IV, are not nearly 

 so striking as in the case of those made into the trees in Cuba. As 

 has been brought out in the previous discussions, the inoculations 

 can be made to take only where the disease is found to occur natur- 

 ally — in the heart tissues — and the heart tissues of all of these 

 sprouted coconuts were very limited. In each of these inoculations 

 the tissues were well water-soaked, which certainly was due to the 

 presence of the bacteria, as the check inoculation failed to show any 

 effect whatever. One inoculation especially — that of 508 — seemed 



228 



