STEWART'S DISEASE OF SWEET CORN (MAIZE). 105 



2 yellow ones, and the internodes show many yellow bundles and some places where the bacteria have 

 oozed out into the parenchyma, forming bright yellow spots. The basal part cut longitudinally shows 

 2 brown nodes ; some of the bundles of the internodes are blackened and a few yellow ones show the 

 bacterial ooze. 



L,IX. Cut 2 inches from the base, the stem shows a few yellow bundles with the characteristic 

 ooze. The longitudinal section shows one node slightly brown. One bundle in the internode is very 

 markedly yellow in color; several other bundles are slightly colored with the yellow bacteria. There 

 are 2 ears, both badly gnawed by larvae (southern corn worm), but both show numerous yellow bundles 

 at the uninjured base. A cross-section in the internode 1 foot above the first cut shows about 20 

 bundles giving out the yellow ooze. There are brownish yellow nodes and yellow bundles in the inter- 

 nodes for a distance of a foot up from the root. Farther up the disease is less distinct, and after one 

 reaches the height of about 3 feet the bacterial slime ceases to be visible to the naked eye or with the 

 hand lens. 



L,X. Cut 3 inches from the root, there is a yellow ooze from a great many bundles. Cut a foot 

 higher, the number of visibly infected bundles is still a good many. Cut another foot up, I see a 

 yellow ooze from only about one dozen bundles. Cut immediately under the male inflorescence, 

 another foot up, the visible infection is reduced to 3 bundles. There are 3 ears, all gnawed by larva, 

 but all showing the yellow bacterial infection at the uninjured base. The base of the stem cut longi- 

 tudinally shows 2 very brown nodes and internodes with many yellow bundles and some very brown 

 ones. The middle internodes sliced longitudinally show numerous yellow bundles. Above the lower 

 (brown) nodes are yellow nodes, from which the bacteria can be seen to ooze on section. 



LXI. Main stem sliced across a node 3 inches from the base, there is yellow bacterial ooze from 

 many bundles. Cut a foot higher, distinct yellow ooze can be seen from about 15 bundles. This 

 portion of the stem slit longitudinally shows yellowish gummy nodes and bright yellow bundles in the 

 internodes. The base cut longitudinally shows the 2 lower nodes markedly brown, the one above 

 brownish yellow, the internode showing yellow bundles. Visible infection runs out about 3 inches 

 under the male inflorescence. There are 2 medium-sized ears and 3 very small ears. Yellow bac- 

 terial ooze shows only in the base of the largest ear (cob). The upper part of this plant contains a 

 much less quantity of the yellow bacteria than many of the others. 



LXII. A small plant, that is, about 3 feet high. Cut 3 inches from the base, many bundles of 

 the internode show the yellow ooze. The basal portion slit longitudinally shows 2 brown nodes, with 

 some yellow bundles in the internodes. One of the inner husks of the ear is infected, and the dis- 

 tinctly yellow bacteria have oozed out of the spots and lie free on the inner surface of the husk. There 

 are numerous yellow bundles in the base of the cob. The middle internodes sliced longitudinally 

 show distinctly yellow stripes corresponding to the infected bundles. Farther up the stem there are 

 numerous areas where the bacteria have oozed out into the parenchyma. In the node just below the 

 male inflorescence there are numerous yellow bundles. 



LXIII. Cut 4 inches from base, there is a distinctly yellow bacterial ooze from a great many 

 bundles, at least 100. Stem sliced longitudinally for a distance of 1.5 feet above the basal cut, the 

 lower nodes are brown and the upper ones are yellowish brown. The internodes are greenish white, 

 with many yellow bundles. The infection can be traced as far up as the slicing. Stem above this 

 broken off. One medium-sized cob, badly infected. At least 4 bundles show yellow ooze in the very 

 tip of the cob. This cob bears no well-developed kernels, probably because it is so badly infected. 

 There are numerous yellow bundles in the husks, and numerous areas where the bacteria have oozed 

 through to the surface (inner face) of husk. One small ear, gnawed by insects, shows yellow bundles 

 at the uninjured base. The base of the stem cut longitudinally shows 3 brown nodes; the whitish 

 internodes show yellow stripes (bundles) with bacteria oozing out in many places. 



LXIV. Cut 3 inches from base, yellow slime oozes from nearly every vascular bundle. Basal 

 portion slit longitudinally, the 3 basal nodes are brown and the greenish-white internodes have bright 

 yellow bundles. The disease runs into the base of one of the ears. The bundles of the leaf-sheaths 

 are occupied, and the bacteria have also made spots in the parenchyma and oozed out as yellow slime 

 on the inside of the leaf-sheaths. A section of stem about a foot above the basal cut shows plenty of 

 bacteria in the vessels ; bacteria are also present as a yellow ooze from the bundles a foot above the 

 last cut. One small ear shows yellow bundles very near the tip of the cob. The husks also show 

 numerous water-soaked spots where the bacteria have oozed from the vascular bundles. Another 

 small cob higher up the stem is slightly infected at the base. Slit the middle section of the stem longi- 

 tudinally and examined the internodes. There are many yellow bundles. To the unaided eye the 

 disease runs out in the upper 18 inches of the stem. 



LXV. Top broken off. An abundance of good roots, as in case of nearly every one of these 

 plants. Cut 3 inches from the base, there is a yellow ooze from nearly every bundle. Base slit longi- 

 tudinally shows the lowest 3 nodes brown, the internodes white, with numerous bright yellow bundles. 



