108 BACTERIA IN RELATION TO PLANT DISEASES. 



The plant was broken off about 1.5 feet below the tassel. A cross-section 3 inches from the base 

 shows very few bundles with the yellow ooze. A longitudinal section of this base shows but one 

 bundle clearly marked with the yellow ooze. Several more longitudinal sections were made, and 

 other bundles were found which showed the yellow discoloration. 



LXXVII. There are two medium-sized ears, neither of which shows any bundles infected with 

 bacteria. A transverse section of the stem 3 inches above the base shows a brown discolored area on 

 the periphery, but there are no bundles which show the bacterial ooze from the cut surface. In longi- 

 tudinal section the nodes at the base of the stem are quite brown, but the disease, if present, runs out 

 about half-way up the stem, as the 3 uppermost nodes appear to be perfectly normal. A hasty micro- 

 scopic examination of the basal part of the stem shows i or 2 bundles infected with bacteria. 



LXXVIII. A transverse section of the stem 3 inches above the root shows numerous bundles 

 from which there is a yellow bacterial ooze. The basal nodes are slightly brown, and there are many 

 yellow and brown bundles in the internodes. The nodes higher up are yellow, and there are 2 or 3 

 yellow bundles in the uppermost node of the stem. In all the internodes above the basal cut yellow 

 bundles can be seen. In the third internode above the basal cut the bacteria have oozed from a 

 bundle into the parenchyma. This is also the case in some of the upper internodes. This plant is 

 very badly infected all the way up to the uppermost node. There is one developed ear, which shows 

 the bacterial ooze at the base of the cob in several places. The bacteria disappear one-third the way 

 up the cob. None of the husks shows any signs of the bacteria. 



LXXIX. On the surface, at the very base of the stem, there are 3 places which are blackish- 

 brown, and the epidermis is dead. The discoloration does not extend inward to any great distance. 

 A transverse section of the stem 3 inches above the base shows a few bundles from which there is a 

 yellow bacterial ooze. In longitudinal section the lower nodes are distinctly brown, while the upper 

 nodes are yellow. In the node just below the tassel, yellow bacterial ooze can be seen issuing from at 

 least one bundle. In the middle internode numerous yellow bundles can be seen. The one ear shows 

 numerous places where the bacteria have come out in an ooze. A few of the husks show a very 

 marked wet spot, i. e., bacterial ooze extending through several of the husks in the same place. 



L,XXX. A cross-section 3 inches from the base shows no bundles colored by the bacteria. A 

 longitudinal section of this base contains 3 nodes of a slightly brown color, but no bundles can be seen 

 that contain the bacteria. The first two nodes above the basal cut are brown. Those higher up 

 show no distinct coloration. With a hand-lens it is impossible to tell whether there are any bacteria 

 present ; but a microscopic examination of material taken from one of the upper nodes shows the pres- 

 ence of the bacteria. A cross-section at the base of the one ear fails to show any bacteria with a 

 hand-lens. 



LXXXI. This is a smaller plant than most of the preceding. A cross-section 3 inches from the 

 base shows very many bundles with the yellow ooze. These bundles may be traced in the longi- 

 tudinal section from the cut to the extreme basal end of the stem ; the 2 nodes are brownish in color. 

 A cross-section of the stem a foot above the first cut shows numerous bundles containing the yellow 

 bacteria. Another foot higher, which is 6 inches below the male inflorescence, the cross-section 

 shows possibly half a dozen bundles containing the bacteria. All of the nodes are somewhat browned. 

 The upper 3 or 4 contain much yellow slime. The plant has two ears, both of which at the base show 

 numerous bundles from which there is a yellow bacterial ooze. In the larger ear most of the yellow 

 bundles run out into the husks, but a few of the bundles can be traced at least one-third of the way up 

 in the center of the cob. In the smaller cob all of the infected bundles seem to run out into the husks. 



LXXXII. On surface around the basal nodes of this plant there are numerous brown cracks. 

 A transverse section of the stem 3 inches above the base shows nearly every bundle filled with the 

 yellow bacteria. Split the stem longitudinally the 6 basal nodes show a brownish color, while all of 

 those higher up are yellowish from the presence of the bacteria. There are numerous yellow bundles 

 in all the internodes. At one place in the uppermost internode the bacteria have oozed into the par- 

 enchyma. There is one developed ear, the pedicel of which shows numerous bundles containing the 

 bacteria. These bundles appear mostly to run out into the husks, where a surface ooze may be seen 

 in numerous places. There is also a place in one of the lower internodes where the bacteria have 

 oozed out of a bundle into the parenchyma. 



LXXXIII. A cross-section 3 inches from base shows numerous bundles with the yellow bac- 

 terial ooze. There are 3 nodes below this cut, all of a brown color. The internodes show several 

 bundles very distinctly marked with the yellow bacteria. They are especially noticeable on the 

 edges (periphery). A longitudinal section of the stem above this cut shows 2 nodes of a brown color 

 and all the upper nodes yellowish in color (the normal color is white or greenish white). In places 

 in the internodes the bacterial masses are plainly seen in the bundles. In other places they can not 

 be so clearly seen with a hand-lens. There is one ear which shows many infected bundles at the 

 base. The greater number of these bundles run out into the husks. 



