Bui. 611, U. S. Dept of Agriculture. 
Plate II. 
Diseased and Healthy Persian Walnut Twiqs and a Nut Affected with 
Walnut Blight. 
A on 1 B, typical cankers produced on twigs in one month's time by needle punctures from 
pure culture; C, n control twig punctured with a sterile needle; D, a diseased nut one 
month after being inoculated from a pure culture by a needle puncture. 
