178 Obscrz'afioji of the Oriyiii of raricfics. 



partial if not to complete predominance. The success 

 of the experiment of course depends on factors still 

 unknown to us, for it is by no means always successful. 

 My belief in these principles, which Darwin himself 

 often refers to, led me to pay special attention, from the 

 very outset of my experiment, to part-curves, i. e., to 

 curves derived from the lateral flowers of the single 

 plants (seep. 173). It is useless to give the numerous cases 

 which afforded no indication of a latent character, and 

 so I will proceed at once to that plant which was the 

 first to do so. It was a specimen of the 21 -rayed race 

 of 1896, which had 21 ray-florets in its terminal in- 

 florescences and gave the following part-curve on the 

 12th of August : 



L. F. 14 15 16 17 18 19 20 21 22 

 No. 1^ 1 1 2 2 2 3 3 4 



I refer to this plant as No. Ir^ in order to indicate 

 that it belonged to the same culture as Nos. la and 1^ 

 whose part-curves were given on page 175. It agrees 

 with those two plants in the fact that there is not a trace 

 of a maximum at 13; but it differs from them and from 

 all the other plants that were examined on the same bed, 

 by the possession of four flowers with 22 rays. On no 

 other plant was there a single lateral flower with more 

 than 21 ra3^s. 



This indication was no doubt pretty small. It would 

 not have been discovered but for the counting of the 

 ligulate florets. Without this statistical method of in- 

 vestigation it would certainly never have been grasped, 

 for the plant Ir grew in a culture of about 1500 speci- 

 mens. It was noted first, along with 500 others, as hav- 



^ Berichte d. d. hot. Gcs., Vol. XVII, p. 91, where No ir is given 

 as No. 12 in the series. 



