FLAX AND TOBACCO 171 



made to produce any quantity of seed ranging from a single pod up to 

 a large inflorescence by appropriate regulation of the quantity of soil 

 in which the plant grows." 



Plants grown in 12-quart buckets produced large amounts 

 of seed when the length of day was shortened by placing the 

 plants in the dark chamber for a part of the normal day. A 

 control series left out of doors during the experiment began to 

 show flower heads about the middle of August (see Fig. 38). 

 Plants exposed to seven hours of light daily produced large quanti- 



FIG. 38. Control series of Maryland Mammoth tobacco in twelve-quart 

 buckets left out of doors during the experiment. Flower buds just beginning 

 to show when photographed, August 19, 1919. (Courtesy of Garner.} 



ties of seed while those exposed to twelve hours of light daily 

 grew larger but were later in blossoming (see Fig. 39). 



In southern Florida during the ordinary winter months, the 

 Maryland Mammoth behaves as ordinary tobacco, showing no 

 evidence of its tall late habit. Thus quantities of seed could 

 easily be produced under these conditions. 



Allard (1919) crossed normal varieties with the Mammoth 

 type. The F\ averaged somewhat higher in leaf number than the 



