Ranunculus Bulbosus Semiplenus. 255 
flowers out of consideration. But even these did not 
manifest any notable differences. I then compared these 
ten curves with the part-curves determined from the 
parents themselves (i e., with the number of flowers 
counted on the seed-parents) and found no correlation. 
As a matter of fact the seed-parent with the smallest 
number of pleiopetalous flowers had the offspring with 
the largest number. The following four curves of the 
offspring of four seed-parents are extracted from my 
records. Under M are given the numbers of petals in the 
seed-parents of 1891. 
M NUMBER OF PETALS PER FLOWER 
5678 9 10 11 12 13 14 IS 16 17 18-23 Totals 
C 510 37 47 81 81 85 102 47 31 63410 525 
C 610 25 67 80 75 117 77 75 45 30 10 6 1 2 3 613 
C 611 54 53 62 78 87 60 59 37 10 4 4 1 1 1 511 
C 711 52 57 76 77 95 64 26 13 460 
Another fact which points in the same direction is 
that the plant which seemed to be far the best in the 
summer of 1891, inasmuch as the apex of its curve was 
over 11-12 petals, had offspring whose character cor- 
r^sponded exactly with that of the whole culture of 1892. 
The improvement on the seed-parent therefore did not 
justify the expectation of a real advance. 
For these reasons I then discontinued the experiment. 
It seemed to me that the impossibility of raising the 
double race from my half race by simple selection was 
placed beyond all doubt. This result could only be ex- 
pected from a further mutation. 
The extensive material afforded by these cultures 
has been utilized to find out how far the number of petals 
per flower in the half race is determined, apart from 
selection, bv internal causes, and how far bv external. 
