250 Non-Isolable Races. 
above, which were made in the original locality. Then 
there are two curves for 1891. In this year I had a 
culture of about four square meters from which I re- 
moved, about the beginning of August all plants which 
had not produced any pleiopetalous flowers as well as 
those which had not yet bloomed. For two weeks I 
counted every flower which appeared on the remaining 
specimens. They amounted to 128 and the various de- 
grees of the anomaly were distributed over them as 
follows : 
Number of petals 5 6 7 8 9 10 11 12 13 
Number of flowers 45 24 28 17 8 4 1 1 
The curve E 1891 in Fig. 51 is based on these figures. 
It is a half curve like the previous one, but without the 
steep apex. The disappearance of this is due partly to 
cultivation and to the repeated selection, but partly also 
to the fact that the individuals with the smallest number 
of pleiopetalous flowers had been removed before the 
counting took place. 
After these data had been determined I carried out 
a still further selection. Several plants had not produced 
a single flower with more than seven petals. These were 
removed in the middle of August and observations on 
the rest were continued. There were 18 plants, all of 
which were selected for seed-parents as being the best 
representatives of the race. I counted all the flowers 
which bloomed from August 15 to 31, and obtained the 
following numbers: 1 
Number of petals 5 6 7 8 9 10 11 12 13 14 
Number of flowers 9 17 39 64 45 37 15 9 6 2 
1 In the preliminary account of this experiment, mentioned 
above, this series is given separately in two curves, one of which 
refers to the most abnormal plant, the other to the rest. 
