PLATE i 
A. —(i, 2) Leaves from mosaic Green Mountain plant. (3) Leaf from healthy 
Green Mountain plant. 
B. —(1) Mild mosaic Green Mountain. (2) Medium plus mosaic Green Mountain. 
C. —(1) Healthy plant from half-tuber seed piece. (2) Mild mosaic plant from a half¬ 
tuber seed piece. Both from same hill of the preceding season. Green Mountain 
variety. 
(n8) 
