cobb's disease of sugar-cane. 43 



Old mature stem. Sound at base. Basal buds well developed. Upper part leafy. Cross- 

 sectioned every internode. One red bundle about 4 feet from the ground. The stain passes from 

 the node into the internode below and runs out; it is slight, and confined to 2 or 3 bundles. Down 2 

 internodes there are two bundles with red stain; this also runs through the node into the upper por- 

 tion of the next internode and then ceases. The lower 2 feet of the cane has occasional red bundles, 

 very few and scattered. 



Old cane. Bears label 87a. Sound at the base. Basal buds well developed. Only a few living 

 leaves. Top of cane dead and a sort of water-soaked brown rot (frost?). No bacterial rot. This 

 condition runs out about 4 feet from the ground. From this point down the cane throughout is 

 sound within. No evidence of infection with Cobb's disease. 



General Remark. Under the hand-lens I can see no indications of bacterial ooze from 

 these stained bundles. No distinct indication of Cobb's disease in these plants. 



This completes observations on the inoculated row of the Common Green cane. 



Blanca. 



North (inoculated) row of this variety: 



Old cane. Sound at the base. Leafy in upper half of the stem, the leaves quite green and of 

 good appearance. On cross-sectioning the stem, found no signs of disease, with the exception of one 

 red bundle about 4 feet from the ground, which soon runs out. 



Old stem. Sound at the base. Bears labels 90a and gob. Leafless nearly to the top. Basal 

 buds well developed. Stem looks sound externally and ripe. Made cross-sections and found the 

 whole interior sound. A very juicy, sweet cane. 



A large old cane. Sound at the base. Basal buds well developed. Leaves on the lower half 

 dead. Stem looks sound externally. Cross-sectioned the stem and found the interior sound in every 

 internode from top to base. 



Old cane. Sound at the base. Bears label Sgb. Only upper leaves living. Cane is sound 

 externally and appears to be mature. Basal buds well developed but not pushing. Cross-sectioned 

 stem in every internode and found the interior sound. 



Old shoot. Sound at the base. Leafy only near the top. Stem well developed. Sound exter- 

 nally. Basal buds well developed, but not pushing. Cross-sections of stem show interior to be 

 sound throughout. 



Old stem. Sound throughout. 



Old mature stem. Only the upper leaves living. Bears label SSa. Basal buds well developed 

 but not pushing. Looks healthy. Cross-sectioned every internode; stem free from disease. Avery 

 juicy, sweet cane. 



Old stem. Sound on cross-section at the base. Upper part leafy and leaves healthy. Basal 

 part of the cane looks healthy also. Cross-sectioned every internode and found the whole plant 

 healthy. 



There are 4 or 5 young shoots from this stool, but all look so healthy that I have refrained from 

 cutting them out. 



General Remark. No evidence of Cobb's disease in this row. This is the end of the 

 inoculated Blanca. 



Jamaica. 



The two rows of Jamaica have sent out a great many suckers, which now bear green leaves and 

 are about 4 or 5 feet high. The notes are on the north (inoculated) row. 



Old cane. Sound at base. Rotted at the top, but not with Cobb's disease. 



Another old cane. Label 91a and 916. Leafy above. Leaves green. Cane looks sound exter- 

 nally. Basal buds well developed. Made cross-sections of stem from top downward in every inter- 

 node and found cane sound until about 4 feet from the ground, when a few red bundles appeared, 

 which soon ran out. These red bundles showed no bacterial ooze. Sound at base. No certain indi- 

 cations of Cobb's disease. Cane very tender, juicy, and sweet. 



Old cane. Sound at base. Basal buds well developed. Cane mature. Top bears green leaves. 

 Made cross-sections from the top downward. Found the interior sound for a number of feet, then 

 came to an internode about 5 feet from the ground with some red bundles. These continue through 

 several internodes, becoming more numerous at about 3 feet from the ground. At this level there are 

 about 15 of these unsound bundles. Disease continues in the next internode below and the one below 

 that, but runs out in the next lower one. Throughout this region the exterior of the cane appears to 

 be almost perfectly sound, there being only a trace of reddening here and there in the nodes and inter- 



