420 



F. M. Rolfs 



disorganized (Fig. 70). Radial rifts or pockets in the young wood and 

 cortex extend outward, often to the epidermis. As the twigs increase in 



Fig. 70. — Cross section of a young peach twig inoculated loith a 'pure culture 

 of Bacterium Pruni obtained from a plum. twig. Bacterial pockets are most 

 abundant in the cortical parenchyma. All cortical parenchyma cells in 

 the infected region are distorted. The bacterial pockets in the cambium 

 region also are to be noted. Occasionally the large ducts in the young 

 wood are filled ivith the organism , 



size these rifts open and form an approximately longitudinal fissure. The 

 bacteria escape through these fissures in countless numbers as bacterial ooze. 



