XXIV LIST OF ILLUSTRATIONS 



PAGE 



270. Leaves and stems of mulberry from Georgia attacked by Bacterium 



mori 350 



271. South African mulberry disease due to Bacterium mori. Section of a 



leaf showing a bacterial pocket 352 



272. A. Flagella of the South African mulberry parasite. B. The South 



African mulberry organism in the tissues 353 



273. Flagellate rods of Bacterium mori from the United States 355 



274. a, b. Appearance of agar poured plate colonies of Bacterium mori with 



different lightings. X 10 356 



275. A single surface colony of Bacterium mori further enlarged by oblique 



light to show internal markings 357 



276. Healthy and blighted branch of a Maryland pear tree. A detail 360 



277. Branch of an apple tree, showing flowers, fruits and shoots blighted by 



Bacillus amylovorus (Burrill) Trevisan 361 



278. Pear tree showing recently blighted limbs. At A', dead blight of the 



preceding year 362 



279. Pear blight on apricot in Washington, D. C 363 



280. Blighting pear leaves collected in Washington, D. C. May, 1915 364 



281. Shoot of Clapp's Favorite pear inoculated 5 days with a pure culture of 



Bacillus amylovorus 366 



282. Apple blight canker (Waite's hold-over blight). Spring condition- 



extruding bacteria 367 



283. A detail above figure 282 enlarged six times to show bacterial ooze 



from a limb 368 



284. Inoculated green pear fruit rotted by Bacillus amylovorus. It shows 



stomatal ooze in many places 369 



285. Blighting pear petiole. A detail from figure 280 showing the copious 



bacterial ooze from many stomata 370 



286. Cavities in a pear shoot due to Bacillus amylovorus. Only the cortical 



parenchyma is attacked 371 



287. A detail from figure 286 showing the bacteria. Inoculation of 1915 



on a young shoot of Clapp's Favorite. Time, 5 days 372 



288. Rods of Bacillus amylovorus as ordinarily seen in disintegrating tissues of 



pear fruit (fig. 284) 373 



289. Texas pear orchard destroyed by blight 375 



290. A, B. Pear trees in Maryland orchard, showing recovery from blight 



due to tree-surgery 376 



291. Flagellate rods of Bacillus amylovorus 377 



292. Surface and buried colonies of Bacillus amylovorus from agar-poured 



plates: A, 1905; B, 1915 378 



293. A, B. Surface and buried colonies of Bacillus amylovorus on agar plates 



photographed by transmitted light; A, direct light; B, oblique light . . 379 



294. Buried and surface gelatin colonies of Bacillus amylovorus after 3 days 



at 21 C 381 



295. Action of Bacillus amylovorus on milk in the closed end of a fermentation 



tube 382 



296. Inoculated browned blighting pear shoot, showing beads of bacterial 



ooze. Variety "Blight-proof " 383 



296*. Pyrus ussuriensis Maxim., a species resistant to fire-blight 388 



