PLATE 2 2 



A. — Healthy turnip plant, control to B. Aphids from healthy turnip were allowed 

 to feed on this plant. Planted the same time as B. 



B. — Mosaic on turnip plant, variety Seven Top or Southern. Mosaic mottling 

 appeared 26 days after the introduction of aphids from a mosaic Southern turnip 

 plant. 



C. — Leaf from A, healthy. 



D, E. — Two mosaic leaves from B. Mosaic mottling and ruflSing apparent on the 

 diseased leaves. 



65508°— 21 5 



I 



