Pelargonium zonale (Geraniaceae).—­Almost sterile; one plant produced two fruits.  It is probable that different varieties would differ in this respect, as some are only feebly dichogamous.

Dianthus caryophyllus (Caryophyllaceae).—­Produces very few capsules which contain any good seeds.

Phaseolus multiflorus (Leguminosae).—­Plants protected from insects produced on two occasions about one-third and one-eighth of the full number of seeds:  see my article in ‘Gardeners’ Chronicle’ 1857 page 225 and 1858 page 828; also ‘Annals and Magazine of Natural History’ 3rd series volume 2 1858 page 462.  Dr. Ogle (’Popular Science Review’ 1870 page 168) found that a plant was quite sterile when covered up.  The flowers are not visited by insects in Nicaragua, and, according to Mr. Belt, the species is there quite sterile:  ‘The Naturalist in Nicaragua’ page 70.

Vicia faba (Leguminosae).—­Seventeen covered-up plants yielded 40 beans, whilst seventeen plants left unprotected and growing close alongside produced 135 beans; these latter plants were, therefore, between three and four times more fertile than the protected plants:  see ‘Gardeners’ Chronicle’ for fuller details, 1858 page 828.

Erythrina (sp.?) (Leguminosae).—­Sir W. MacArthur informed me that in New South Wales the flowers do not set, unless the petals are moved in the same manner as is done by insects.

Lathyrus grandiflorus (Leguminosae).—­Is in this country more or less sterile.  It never sets pods unless the flowers are visited by humble-bees (and this happens only rarely), or unless they are artificially fertilised:  see my article in ‘Gardeners’ Chronicle’ 1858 page 828.

Sarothamnus scoparius (Leguminosae).—­Extremely sterile when the flowers are neither visited by bees, nor disturbed by being beaten by the wind against the surrounding net.

Melilotus officinalis (Leguminosae).—­An unprotected plant visited by bees produced at least thirty times more seeds than a protected one.  On this latter plant many scores of racemes did not produce a single pod; several racemes produced each one or two pods; five produced three; six produced four; and one produced six pods.  On the unprotected plant each of several racemes produced fifteen pods; nine produced between sixteen and twenty-two pods, and one produced thirty pods.

Lotus corniculatus (Leguminosae).—­Several covered-up plants produced only two empty pods, and not a single good seed.

Trifolium repens (Leguminosae).—­Several plants were protected from insects, and the seeds from ten flowers-heads on these plants, and from ten heads on other plants growing outside the net (which I saw visited by bees), were counted; and the seeds from the latter plants were very nearly ten times as numerous as those from the protected plants.  The experiment was repeated on the following year; and twenty protected heads now yielded only a single aborted seed, whilst twenty heads on the plants outside the net (which I saw visited by bees) yielded 2290 seeds, as calculated by weighing all the seed, and counting the number in a weight of two grains.