PLATE 3 
A. —Scarlet Globe radish plants, from seeds which germinated May 19. These 
plants were prevented from flowering by exposure to a day length of only seven hours 
till October 20, when they were transferred to the greenhouse and allowed to receive 
the full natural period of daily illumination during the months of November, December 
and January. By February 1, one of the plants showed evidence of elongating a 
flowering stem in response to the increasing length of day, and the daily light penod 
was again shortened to seven hours. Elongation of the stem was soon slowed down. It is 
seen from the photograph that branching is confined chiefly to the upper portion of the 
stem. The first blossom appeared March 20. Photographed April 17. 
B. —Final stages of development of the radish plant shown in A, at right. It is seen 
that the type of development has been markedly changed by continued exposure to 
seven hours of light daily. Progressive weakening in power to elongate the primary 
axis is accompanied by increased transfer of activity to the lower branches. Thus, 
the effect is to change the general contour of the plant to conform more nearly with 
that of many woody perennials. It will be observed that the weak, pendent stems 
which eventually appeared, grew to unusual lengths. These are typical effects of a light 
period which is markedly suboptimal for increase in stature. Photographed June 2. 
