PLATE 9 
A, —Large area of blighted spinach on farm E, eastern Virginia. (Original.) 
B. —Three spinach plants inoculated with virus-bearing Macrosiphum solanifolii, 
first instar. Symptoms on the infected plant (a) developed 41 days previous to the 
time this photograph was taken. The two large plants (6 and c) did not become 
infected and are healthy. (OriginaL) 
