PLATE 2 
A. —Growth to be seen in midsummer, the reproductive stage having been 
started by the spring days of intermediate length, then arrested by the long 
days of summer, with a resumption of vegetative growth. Photographed August 
1, 1923. 
B. —Normal vegetative development, showing the short leafed, short inter- 
nodalfgrowth made in the shorter days, in contrast with the later growth of large 
leaves, and|long internodes typical of growth made in the longer days. Photo¬ 
graphed May 9, 1923. 
