566 
Journal of Agricultural Research 
Vol. XXXI, No 6 " 
full length of day. When, however, the lower portion of the axis 
received the light of the long summer day and therefore was pre¬ 
vented from flowering, while the upper portion was maintained in 
continuous darkness, the latter formed no flower buds and resumed 
vegetative activity when returned to the light. 
When the entire plant was excluded from the light for a period of 
10 days and then returned to the action of the long day, flower buds 
did not appear. 
These tests seem to indicate that, under the conditions, continuous 
darkness in itself does not definitely initiate flowering, but that, on 
the other hand, it does not necessarily inhibit formation of flower 
buds in response to the action of a short daily light period on another 
part of the plant. 
