Jul. 40, U. S. Dept. of Agncultur 



Plate V!. 



Fig. 1.— Healthy and Mosaic Plants of Nicotiana silvestris. A, Healthy Plant; 

 B, Diseased Plant Produced by Artificial Inoculation. 



(Greatly reduced.) 



Fig. 2.— Healthy and Mosaic Plants of Nicotiana tabacum. A, Healthy Plant; 

 B, Mosaic Plant, Showing Symptoms of the Disease Following Infestation 

 with Aphides. 



Hundreds of mosaic plants were obtained in this manner as a result of aphid infestation. 



(Greatly reduced.) 



