26 



UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



rot. Instead of the entire underground portions being soft, watery, 

 and decayed, the woody cylinder suffers no outward disorganization, 

 but is more or less discolored according as it is examined nearer to or 

 farther from the original center of infection. In fact, so slight is the 



FIG. 5. Young vine killed by Root-rot. 



decay of the tissues that a vine, when cursorily examined after it has 

 been dug out, shows no signs of a specific disease. The bark on the stem 

 is tight and dry, and is not suggestive ; on the roots it is often streaked 

 with filmy white, but even this is not characteristic enough to hold 



