356 
T. H. GOODSPEED AND R. E. CLAUSEN 
COROLLA SPREAD IN MILLIMETERS 
Fig. 3. Frequency polygons of variation for corolla spread of 13 2210^. 
2. Age of Flower'' Factor 
Under this heading, "'Age of Flower' Factor," we desire to illus- 
trate two rather distinct sets of phenomena with reference to flower 
size in Nicotiana; first, the fact that at any given date throughout 
the flowering season the flowers on the terminal inflorescence difi^er 
in size from those borne on the laterals which come into flower late 
in the growing season, and second, the fact that with reference to 
apparently fully opened flowers, those with anthers shedding pollen 
are larger than flowers which are not shedding pollen. Tables XIa, 
XI&, Xlla, XII&, Xllla, XIII&, XlVa, Xm, XVa, and XV& illustrate 
these points. 
