Chapter 5

GERANIACEAE, LEGUMINOSAE, ONAGRACEAE, ETC.

Pelargonium zonale, a cross between plants propagated by cuttings does no good.
Tropaeolum minus.
Limnanthes douglasii.
Lupinus luteus and pilosus.
Phaseolus multiflorus and vulgaris.
Lathyrus odoratus, varieties of, never naturally intercross in England.
Pisum sativum, varieties of, rarely intercross, but a cross between them highly beneficial.
Sarothamnus scoparius, wonderful effects of a cross.
Ononis minutissima, cleistogene flowers of.
Summary on the Leguminosae.
Clarkia elegans.
Bartonia aurea.
Passiflora gracilis.
Apium petroselinum.
Scabiosa atropurpurea.
Lactuca sativa.
Specularia speculum.
Lobelia ramosa, advantages of a cross during two generations.
Lobelia fulgens.
Nemophila insignis, great advantages of a cross.
Borago officinalis.
Nolana prostrata.

13. GERANIACEAE.--Pelargonium zonale.

This plant, as a general rule, is strongly proterandrous, and is therefore adapted for cross-fertilisation by the aid of insects. (5/1. Mr. J. Denny, a great raiser of new varieties of pelargoniums, after stating that this species is proterandrous, adds 'The Florist and Pomologist' January 1872 page 11, "there are some varieties, especially those with petals of a pink colour, or which possess a weakly constitution, where the pistil expands as soon as or even before the pollen-bag bursts, and in which also the pistil is frequently short, so when it expands it is smothered as it were by the bursting anthers; these varieties are great seeders, each pip being fertilised by its own pollen. I would instance Christine as an example of this fact." We have here an interesting case of variability in an important functional point.) Some flowers on a common scarlet variety were self-fertilised, and other flowers were crossed with pollen from another plant; but no sooner had I done so, than I remembered that these plants had been propagated by cuttings from the same stock, and were therefore parts in a strict sense of the same individual. Nevertheless, having made the cross I resolved to save the seeds, which, after germinating on sand, were planted on the opposite sides of three pots. In one pot the quasi-crossed plant was very soon and ever afterwards taller and finer than the self-fertilised. In the two other pots the seedlings on both sides were for a time exactly equal; but when the self-fertilised plants were about 10 inches in height, they surpassed their antagonists by a little, and ever afterwards showed a more decided and increasing advantage; so that the self-fertilised plants, taken altogether, were somewhat superior to the quasi-crossed plants. In this case, as in that of the Origanum, if individuals which have been asexually propagated from the same stock, and which have been long subjected to the same conditions, are crossed, no advantage