PLATE 7 
A. —(i) Top leaf from healthy Green Mountain. (2, 3) Top leaves from spindling- 
tuber Green Mountain. From plants of C (1, 2). 
B. —(1, 2) Same hills as shown in C (1, 2), earlier in the season (July 6). 
C. —(1) Spindling-tuber Green Mountain from half-tuber seed piece. (2) Healthy 
Green Mountain from quarter-tuber seed piece. Same hills as shown in B f but later 
in the season (August 29). 
