In experiments with this character, in order to be able to discriminate with certainty, the long axis of 6–7 ft. was always crossed with the short one of 3/4 ft. to 1 1/2 ft.
Each two of the differentiating characters enumerated above were united by cross-fertilisation. There were made for the
1st
trial
60
fertilisations
on
15
plants.
2nd