STEWART'S DISEASE OP SWEET CORN (MAIZE). 107 



LXX. There are 4 ears, 3 abortive. The abortive ear nearest the base of the stem is conspicu- 

 ously diseased only at the extreme base. Cut an inch higher up, I can see no evidence of infection 

 with a hand-lens, except in some of the bundles of one of the outer husks. The best ear, which is 

 only a nubbin, shows distinct infection at its base. Cut 1 inch higher up, the bacteria are still present, 

 both in the base of the cob and in the husks. One very small ear shows numerous yellow bundles at 

 the base and also in the husks. Main stem cut 3 inches from the base, there is a yellow ooze from 

 nearly or quite every bundle. Cut 1 foot higher and examined at the upper part, numerous bundles 

 show the yellow ooze. Cut 1 foot higher and examined at the upper cut, there is no distinct infection. 

 Cut 4 inches higher, that is, 1 inch under the male inflorescence, I can not see any distinct signs of infec- 

 tion. The basal portion of the main axis shows 4 brown nodes and the greenish white internodes have 

 conspicuous yellow bundles. 



The foregoing include all of the plants examined up to the date of the first hard frost, 

 the night of October 29. The plants were covered with paper bags at 10 o'clock p. m., but 

 too late to protect them, i. e., when the temperature was between o and i C. The leaves 

 of all the plants were frosted. 



On October 31 most of the plants had recently frosted green foliage, but 16 of them had 

 dried-out white foliage, and these 16 were pulled up separately and taken into the laboratory 

 for examination. My notes on these plants are as follows : 



All the plants, with one exception, had abundant and sound roots. The male inflores- 

 cence, where present, was dried up, and all the leaves were dried and shriveled. The plants 

 were from 4 to 4.5 feet high. The stems of all the plants were green. 



LXXI. The stem cut 3 inches above the root shows no bacterial ooze from the bundles. The 6 

 lowest nodes are distinctly brown, while the 4 upper nodes are yellow, and there are very many 

 bundles in the upper part of the stem which show the yellow bacterial ooze. A hasty microscopic 

 examination of the portion of the stem between the second and third nodes shows no bacteria in the 

 bundles. There are two ears, one small, which does not show, clearly at least, any bacterial ooze; the 

 larger ear, cut crosswise at the base, that is, across the cob, shows two or three bundles very distinctly 

 marked with the yellow ooze possibly several more, but not clearly seen. In a transverse section of 

 the stem 6 inches below the male inflorescence there are numerous bundles which distinctly show the 

 yellow bacterial ooze. It is especially noticeable around the periphery. 



LXXII. This plant shows very slight signs of the disease. In a cross-section 3 inches from root 

 no ooze could be found. Likewise in a longitudinal section of the base there is no ooze. The lowest 

 node is discolored. The second node is discolored a little. No other nodes show any discoloration 

 whatever. The only bacterial ooze found is in one node about half-way up the stem and in a cross- 

 section in the base of the cob, the yellow slime running out also into a few of the inner husks. 



LXXIII. A transverse section of stem 3 inches above the base shows numerous bundles from 

 which there is a yellow bacterial ooze. In the longitudinal section the lower nodes are brown, with 

 yellow bundles in the internodes. There is one small undeveloped ear, which shows no bacterial 

 growth. A somewhat larger ear badly eaten by insects shows in the uninjured part numerous bundles 

 with yellow bacterial ooze. A few yellow bundles are present in the second node below the tassel. 



LXXIV. This is a very severe case. A cross-section 3 inches from base shows a large number 

 of bundles with a bright yellow ooze. In a longitudinal section of the base these bundles may be 

 traced the entire length by their marked color. The 3 nodes of this base are very badly discolored, 

 being nearly black. In the section above the basal cut, 2 of the nodes show brown discoloration, 

 while the upper 3 show yellowish discoloration. At least 2 yellow bundles can be seen in a transverse 

 section 6 inches below the tassel, in the internode between the tassel and the first node below. There 

 are 2 ears, a small undeveloped one which shows bacteria present at its base, and a larger one which 

 shows numerous yellow bundles at the base, the majority of which run out into the husks. 



LXXV. In a cross-section 3 inches from base of the stem numerous yellow bundles are seen. 

 A longitudinal section of the base shows 3 badly discolored nodes, the internodes having many yellow 

 bundles. The first 3 nodes above the basal cut are distinctly brown in color, while the upper nodes 

 are yellowish. The disease can be traced to a node about 1.5 feet below the tassel. There is one ear 

 on the plant, the base of which shows numerous yellow bundles, nearly all of which run out into the 

 husks and not into the cob. 



LXXVI. A small plant. There is one ear on this plant, the base of which shows numerous 

 bundles from which the yellow bacteria ooze. One of the inner husks has numerous water-soaked 

 spots, from one or two of which the bacteria have broken out to the surface on the inner side of the 

 husk. The upper nodes of the stem show on section a distinct yellow bacterial ooze from the bundles. 



