474 
Syncotylous Races. 
in which the seed-leaves are fused together on both sides 
(Fig. 90, C and D). Fig. 98 represents such a curve 
from the harvest of 1889, which includes 2439 seedlings. 
The absolute numbers of the seedlings which possess the 
various degrees of symphysis are given below the figure. 
The groups are obviously arbitrary, but it is not likely 
that a grouping according to a different scheme would 
have any essential effect on the form of the curve, for 
the seedlings with fused peduncles only would always 
constitute a minimum between the two peaks. 
If we examine the se- 
ries of figures of our pedi- 
gree statistically, we see 
that they are, as a rule, 
asymmetrical, i. e., the 
highest values are closer 
to the one end than to the 
other. In all the years 
with the exception of the 
first and the last, the high- 
est peak is shifted in the 
direction of selection. In 
order to examine this ef- 
fect more closely I insti- 
tuted an experiment in the 
summer of 1890 on a 
At. ^ 
233 20 
I S. 
23 
Y\ K. % K. H K. g AoKA K. B. 
5? 7.0 .175 226 634 
Fig. 98. Helianthus annuus syn- 
cotylens. Curve representing the 
degree of syncotyly in the seed- 
lings of the harvest of 1889. At, 
atavists ; Y 2 S, iS, peduncles 
fused along half their extent or 
entirely; %K, Y 2 K, y 4 K, 9 />K, 
i K, seed-leaves fused over % of 
their extent and so forth ; B, 
pitcher-cotyls or amphicotyls. 
larger scale alongside the 
one dealt with on page 470. For this purpose I planted 
out about 60 syncotyls from a parent with a value of 
81% ; 55 of these gave a sufficient harvest. The values 
have been arranged in groups in the same way as in the 
pedigree on page 470, and the sizes of the groups thus 
obtained, are graphically displayed in Fig. 99 and Hven 
