Fumaria officinalis (Fumariaceae).—­Covered-up and unprotected plants apparently produced an equal number of capsules, and the seeds of the former seemed to the eye equally good.  I have often watched this plant, and so has Hildebrand, and we have never seen an insect visit the flowers.  Hermann Muller has likewise been struck with the rarity of the visits of insects to it, though he has sometimes seen hive-bees at work.  The flowers may perhaps be visited by small moths, as is probably the case with the following species.

Fumaria capreolata.—­Several large beds of this plant growing wild were watched by me during many days, but the flowers were never visited by any insects, though a humble-bee was once seen closely to inspect them.  Nevertheless, as the nectary contains much nectar, especially in the evening, I felt convinced that they were visited, probably by moths.  The petals do not naturally separate or open in the least; but they had been opened by some means in a certain proportion of the flowers, in the same manner as follows when a thick bristle is pushed into the nectary; so that in this respect they resemble the flowers of Corydalis lutea.  Thirty-four heads, each including many flowers, were examined, and twenty of them had from one to four flowers, whilst fourteen had not a single flower thus opened.  It is therefore clear that some of the flowers had been visited by insects, while the majority had not; yet almost all produced capsules.

Linum usitatissimum (Linaceae).—­Appears to be quite fertile.  H. Hoffmann ‘Botanische Zeitung’ 1876 page 566.

Impatiens barbigerum (Balsaminaceae).—­The flowers, though excellently adapted for cross-fertilisation by the bees which freely visit them, set abundantly under a net.

Impatiens noli-me-tangere (Balsaminaceae).—­This species produces cleistogene and perfect flowers.  A plant was covered with a net, and some perfect flowers, marked with threads, produced eleven spontaneously self-fertilised capsules, which contained on an average 3.45 seeds.  I neglected to ascertain the number of seeds produced by perfect flowers exposed to the visits of insects, but I believe it is not greatly in excess of the above average.  Mr. A.W.  Bennett has carefully described the structure of the flowers of I. fulva in ’Journal of the Linnean Society’ volume 13 Bot. 1872 page 147.  This latter species is said to be sterile with its own pollen (’Gardeners’ Chronicle’ 1868 page 1286), and if so, it presents a remarkable contrast with I. barbigerum and noli-me-tangere.

Limnanthes douglasii (Geraniaceae).—­Highly fertile.

Viscaria oculata (Caryophyllaceae).—­Produces plenty of capsules with good seeds.

Stellaria media (Caryophyllaceae).—­Covered-up and uncovered plants produced an equal number of capsules, and the seeds in both appeared equally numerous and good.

Beta vulgaris (Chenopodiaceae).—­Highly self-fertile.