Page:Mendel's principles of heredity; a defence.pdf/70

50 but nevertheless reappear unchanged in their progeny, as will be demonstrated later on.

It was furthermore shown by the whole of the experiments that it is perfectly immaterial whether the dominant character belong to the seed-bearer or to the pollen parent; the form of the hybrid remains identical in both cases. This interesting fact was also emphasised by Gärtner, with the remark that even the most practised expert is not in a position to determine in a hybrid which of the two parental species was the seed or the pollen plant.

Of the differentiating characters which were used in the experiments the following are dominant:
 * 1) The round or roundish form of the seed with or without shallow depressions.
 * 2) The low colouring of the seed albumen [cotyledons].
 * 3) The grey, grey-brown, or leather-brown colour of the seed-coat, in connection with violet-red blossoms and reddish spots in the leaf axils.
 * 4) The simply inflated form of the pod.
 * 5) The green colouring of the unripe pod in connection with the same colour in the stems, the leaf-veins and the calyx.
 * 6) The distribution of the flowers along the stem.
 * 7) The greater length of stem.

With regard to this last character it must be stated that the longer of the two parental stems is usually exceeded by the hybrid, which is possibly only attributable to the greater luxuriance which appears in all parts of plants when stems of very different length are crossed. Thus, for instance, in repeated experiments, stems of 1 ft. and 6 ft. in length yielded without exception hybrids which varied in length between 6 ft. and 7½ ft.