Nolana prostrata (Nolanaceae).—­Plants covered up in the greenhouse, yielded seeds by weight compared with uncovered plants, the flowers of which were visited by many bees, in the ratio of 100 to 61.

Ajuga reptans (Labiatae).—­Set a good many seeds; but none of the stems under a net produced so many as several uncovered stems growing closely by.

Euphrasia officinalis (Scrophulariaceae).—­Covered-up plants produced plenty of seed; whether less than the exposed plants I cannot say.  I saw two small Dipterous insects (Dolichopos nigripennis and Empis chioptera) repeatedly sucking the flowers; as they crawled into them, they rubbed against the bristles which project from the anthers, and became dusted with pollen.

Veronica agrestis (Scrophulariaceae).—­Covered-up plants produced an abundance of seeds.  I do not know whether any insects visit the flowers; but I have observed Syrphidae repeatedly covered with pollen visiting the flowers of V. hederaefolia and chamoedrys.

Mimulus luteus (Scrophulariaceae).—­Highly self-fertile.

Calceolaria (greenhouse variety) (Scrophulariaceae).—­Highly self-fertile.

Verbascum thapsus (Scrophulariaceae).—­Highly self-fertile.

Verbascum lychnitis.—­Highly self-fertile.

Vandellia nummularifolia (Scrophulariaceae).—­Perfect flowers produce a good many capsules.

Bartsia odontites (Scrophulariaceae).—­Covered-up plants produced a good many seeds; but several of these were shrivelled, nor were they so numerous as those produced by unprotected plants, which were incessantly visited by hive and humble-bees.

Specularia speculum (Lobeliaceae).—­Covered plants produced almost as many capsules as the uncovered.

Lactuca sativa (Compositae).—­Covered plants produced some seeds, but the summer was wet and unfavourable.

Galium aparine (Rubiaceae).—­Covered plants produced quite as many seeds as the uncovered.

Apium petroselinum (Umbelliferae).—­Covered plants apparently were as productive as the uncovered.

Zea mays (Gramineae).—­A single plant in the greenhouse produced a good many grains.

Canna warscewiczi (Marantaceae).—­Highly self-fertile.

Orchidaceae.—­In Europe Ophrys apifera is as regularly self-fertilised as is any cleistogene flower.  In the United States, South Africa, and Australia there are a few species which are perfectly self-fertile.  These several cases are given in the second edition of my work on the Fertilisation of Orchids.

Allium cepa (blood red var.) (Liliaceae).—­Four flower-heads were covered with a net, and they produced somewhat fewer and smaller capsules than those on the uncovered heads.  The capsules were counted on one uncovered head, and were 289 in number; whilst those on a fine head from under the net were only 199.]