STEWART'S DISEASE OF SWEET CORN (MAIZE). 



IO9 



LXXXIV. A cross-section 3 inches from the base shows 20 or more bundles with the bacterial 

 ooze. In longitudinal section the base shows 2 slightly browned nodes. The bundles in the inter- 

 nodes are considerably colored by the yellow bacteria. In making this longitudinal section several 

 roots were cut longitudinally. The presence of any yellow material in these roots could not be seen. 

 A longitudinal section of the stem above the basal cut shows 5 brown nodes. The internodes show 

 about half a dozen bundles that are plainly marked (yellow) with the bacterial disease. Two or three 

 yellow bundles can be traced up to the node immediately below the tassel. This plant has one ear, 

 which shows yellow bundles at the base running out into the husks. A few of the infected bundles 

 are visible as far out as the middle of the cob. 



LXXXV. A cross-section 3 inches from the base shows a few bundles occupied by the bacteria. 

 Longitudinal section at base : here 2 discolored nodes and several bundles in the internodes with yel- 

 lowish slime. Above the basal cut there are also 2 brown nodes, the remainder being yellowish. 

 Yellow bundles can be seen in all the internodes. There are two ears, eaten by insects, but on section 

 they show the yellow bacterial ooze issuing from the bundles at the base. 



LXXXVI. This plant possesses very few roots. At surface of the nodes from which the roots 

 spring there are numerous dark brown spots. There are several of these spots in the second and third 

 internodes. In some cases the brown spot has a hole in the center as if, perhaps, it had been eaten 

 by some insect. These holes, together with the brown discoloration, extend inward, in one case 

 as far as the center of the stem. A cross-section 3 inches from the base shows a goodly number of 

 bundles with the bacterial ooze. A longitudinal section of the base shows 3 badly browned nodes, 

 the stain evidently not caused by the outer injury before described. One node, however, shows a dis- 

 coloration of an entirely different nature, which apparently comes from one of the aforesaid black 

 spots on the outer surface. The internodes show bundles with the bacteria. Longitudinal section of 

 the parts above the basal cut shows 3 nodes of a brown color, the remaining upper ones being yellowish 

 or green. Some bundles in all of the internodes show bacteria. There is one ear, which shows at its 

 base a few bundles infected with the yellow bacteria. 



On November 1, all the remaining plants were examined in the field one by one, but 

 it is not worth while to describe any of them minutely, since it would be only a repetition 

 of what has preceded. The results obtained are summarized in table 7. 



Table 7. Number of Cases by Varieties and the Time when the Signs were First Observed. 



