Expt. 1.--Among 565 plants which were raised from round seeds of
the first generation, 193 yielded round seeds only, and remained
therefore constant in this character; 372, however, gave both round
and angular seeds, in the proportion of 3 to 1. The number of the
hybrids, therefore, as compared with the constants is 1·93 to 1.
Expt. 2.--Of 519 plants which were raised from seeds whose albumen
was of yellow colour in the first generation, 166 yielded exclusively
yellow, while 353 yielded yellow and green seeds in the proportion
of 3 to 1. There resulted, therefore, a division into hybrid and
constant forms in the proportion of 2·13 to 1.
For each separate trial in the following experiments 100 plants
were selected which displayed the dominant character in the first
generation, and in order to ascertain the significance of this, ten
seeds of each were cultivated.
Expt. 3.--The offspring of 36 plants yielded exclusively grey-brown
seed-coats, while of the offspring of 64 plants some had grey-brown
and some had white.
Expt. 4.--The offspring of 29 plants had only simply inflated pods;
of the offspring of 71, on the other hand, some had inflated and some
constricted.
Expt. 5.--The offspring of 40 plants had only green pods; of the
offspring of 60 plants some had green, some yellow ones.
Expt. 6.--The offspring of 33 plants had only axial flowers; of the
offspring of 67, on the other hand, some had axial and some terminal
flowers.
Expt. 7.--The offspring of 28 plants inherited the long axis, and
those of 72 plants some the long and some the short axis.
In each of these experiments a certain number of the plants came
constant with the dominant character. For the determination of the
proportion in which the separation of the forms with the constantly
persistent character results, the two first experiments are of especial
importance, since in these a larger number of plants can be compared.
The ratios 1·93 to 1 and 2·13 to 1 gave together almost exactly the
average ratio of 2 to 1. The sixth experiment has a quite concordant
result; in the others the ratio varies more or less, as was only to be
expected in view of the smaller number of 100 trial plants. Experiment
5, which shows the greatest departure, was repeated, and then in lieu
of the ratio of 60 and 40 that of 65 and 35 resulted. _The average
ratio of 2 to 1 appears, therefore, as fixed with certainty._ It is
therefore demonstrated that, of those forms which possess the dominant
character in the first generation, in two-thirds the hybrid character
is embodied, while one-third remains constant with the dominant
character.
The ratio of 3 to 1, in accordance with which the distribution of the
dominant and recessive characters results in the first generation,
resolves itself therefore in all experiments into the ratio of 2 :
1 : 1 if the dominant character be differentiated according to its
significance as a hybrid character or a parental one. Since the members
of the first generation spring directly from the seed of the hybrids,
_it is now clear that the hybrids form seeds having one or other of the
two differentiating characters, and of these one-half develop again the
hybrid form, while the other half yield plants which remain constant
and receive the dominant or recessive characters [respectively] in
equal numbers_.