PLATE 87 



A. — Leaves of Romaine lettuce. Leaf in center from healthy plant; two others 

 from mosaic plants, one showing pronounced type of mottling and the other general 

 yellowish discoloration with few green blotches along larger veins. 



B. — Young expanding leaves of head lettuce from experiment started March 22. 

 Leaf on left from healthy plant; two others from plant in early stage of the mosaic 

 disease, showing yellowish discoloration along smaller leaf veins. 



(74o) 



