358 
T. H. GOODSPEED AND R. E. CLAUSEN 
40 4S- 
COROLLA TUBE LEN(,TH /N MILLIMETERS 
Fig. 4. Frequency polygons of variation for corolla tube length of 13 22/07. 
j85^With reference to the difference in size of fully opened flowers 
before and after the shedding of pollen the data is given in Tables XIa, 
Xlla, and XII&. In these tables the flowers measured before 
shedding pollen, designated "before an thesis" in the tables, are com- 
pared with flowers measured on the same dates on the same plants 
after shedding pollen, designated ''after anthesis" in the tables. In 
the case of 12 (11) Fi H38, the difference between the spread of ''older" 
and "younger" flowers reaches more than 5 mm. for individual plants 
and averages 4.53 zb .23 mm. for the 10 plants measured. A corre- 
sponding condition does not hold for length of corolla where the 
maximum difference in size does not reach 3 mm. and averages only 
1.62 rt .22 mm. For the "older" and "younger" flowers of 13 Fi H137, 
we have the same situation as shown in Tables XI la and XI 15. The 
