Bui. 40. U. S. Dept. of Agriculture. 



Plate IV. 



Fig. 1.— Normal and Mosaic Blossoms of Nicotiana tabacum. 



Top row, normal blossoms. Bottom row, blossoms from mosaic plants showing an ex- 

 tremely depauperate growth of the corollas, so that the stamens and pistils extrude. 

 (Greatiy reduced.) 



Fig. 2.— Sumatra Tobacco Plant which was Inoculated (at A) with the 



Mosaic Disease. 



The first symptoms of the mosaic disease appeared at a and b. The disease became gen- 

 eral at a later period and large basal suckers showed pronounced symptoms of it. 



