Sept. 12 17 22 27 Oct. 
358 BOTANICAL GAZETTE [NOVEMBER 
by those individuals, they yet have higher numbers than the last - 
heads of the mediocre portion of the population which determined 
the minimum mean value. These facts will be made clear by a 
reference to jig. 17, in which the numerous oblique parallel lines 
represent the change in mean number of parts in the heads of the 
individual stems com- 
| posing the population. 
ad) 
The abscissal distances 
of the ends of a given 
line indicate the time 
at which the individ- 
ual represented by that 
line began to bloom 
and that at which it 
ceased blooming, while 
the ordinatal distances 
of the same points rep- 
resent the number of 
parts in the first and 
last heads produced. 
The heavy line running 
through the middle of 
: the figure is the exact 
Fic. 17.—Schematized representation of the mean of the figure “4 
changes in mean number of parts in the heads of the drawn. This figure 1s 
1903 population; each of the parallel oblique lines somewhat schematic, 
represents th ‘ : err 
3 eg s i change ina anee en ; he heavy Ene of couse Dae ae 
- wholly imaginary: The 
and the outline 
Table A, which 
so that jig. 17 
tation of the 
mean is suggested by the 1903 bract-curve of fig. 7: 
will be recognized in the distribution of numbers in 
also belongs to the bracts of the 1903 population, 
may be looked upon as a slightly schematized represem 
aximum to the 
minimum was 11.6 per cent. in bracts, 14-4 pet cent. in rayS, * 
in bracts, 
18.9 per cent. in disk-florets; and in 1903 it was 24.6 per cent. In! oe 
22.3 per cent, in rays, and 26.4 per cent. in disk-florets- This 
