46
Mendel's Experiments
- To the difference in the colour of the seed-coat. This is either white, with which character white flowers are constantly correlated; or it is grey, grey-brown, leather-brown, with or without violet spotting, in which case the colour of the standards is violet, that of the wings purple, and the stem in the axils of the leaves is of a reddish tint. The grey seed-coats become dark brown in boiling water.
- To the difference in the form of the ripe pods. These are either simply inflated, never contracted in places; or they are deeply constricted between the seeds and more or less wrinkled (P. saccharatum).
- To the difference in the colour of the unripe pods. They are either light to dark green, or vividly yellow, in which colouring the stalks, leaf-veins, and calyx participate[1].
- To the difference in the position of the flowers. They are either axial, that is, distributed along the main stem; or they are terminal, that is, bunched at the top of the stem and arranged almost in a false umbel; in this case the upper part of the stem is more or less widened in section (P. umbellatum)[2].
- To the difference in the length of the stem. The length of the stem[3] is very various in some forms; it is,
- ↑ One species possesses a beautifully brownish-red coloured pod, which when ripening turns to violet and blue. Trials with this character were only begun last year. [Of these further experiments it seems no account was published. Correns has since worked with such a variety.]
- ↑ [This is often called the Mummy Pea. It shows slight fasciation. The form I know has white standard and salmon-red wings.]
- ↑ [In my account of these experiments (R.H.S. Journal, vol. xxv. p. 54) I misunderstood this paragraph and took "axis" to mean the floral axis, instead of the main axis of the plant. The unit of measurement, being indicated in the original by a dash (´), I care-
