Gregor Mendel

As a result, each of the two parental traits is realized in half of the offspring; the other half, again, are hybrids which repeat in the next generation the phenomena just described.

The ratio of 3:1, 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 parental plants differ in two characters, then the hybrids resemble one parent in one character and the other parent in the other character.

The behaviour of the pair of differentiating characters in hybrid union is independent of the other differences between the two parental plants.

Constant progeny can only be formed when the egg cells and the fertilizing pollen are of like character.

The difference of the forms among the progeny of the hybrids, as well as the ratios in which they are observed, find an adequate explanation in the principle above deduced.

The results of the experiments previously described led to further experiments, the results of which appear fitted to afford some conclusions as regards the composition of the egg and pollen cells of hybrids.

It remains therefore purely a matter of chance which of the two sorts of pollen will become united with each separate egg cell.

The law of combination of different characters which governs the development of the hybrids finds therefore its foundation and explanation in the principle enunciated.

Experiments which in this connection were carried out with two species of Hieracium produced results which differed in the most striking manner from those just given for Pisum.

I have been reared in the country and have therefore from youth upwards been familiar with plant culture; a liking for it grew with my years.

I have undertaken experiments with a small plant, the common pea, which have lasted for eight years.

The object of these experiments was to observe the variations in the offspring of hybrids.

The hybrids from such unions are not intermediate, but they resemble one or other parent.

In the first generation, the hybrid character is constant and uniform.

In the second generation, the offspring of the hybrids split into various forms according to definite laws.

The numerical ratios in which the different forms appear permit of being expressed by a simple formula.

I have been reproached with not having taken into account the opinion of famous authorities. To this I must reply that I did not know of any published work which contained similar experiments continued for such a number of years and carried out on such a scale.

Nature herself supplies the control experiment.

The work is the result of long and patient investigation.