The well-adapted means by which cross-fertilisation is ensured in this genus have been described by several authors. (5/23.  See the works of Hildebrand and Delpino.  Mr. Farrer also has given a remarkably clear description of the mechanism by which cross-fertilisation is effected in this genus, in the ‘Annals and Magazine of Natural History’ volume 2 4th series 1868 page 260.  In the allied genus Isotoma, the curious spike which projects rectangularly from the anthers, and which when shaken causes the pollen to fall on the back of an entering insect, seems to have been developed from a bristle, like one of those which spring from the anthers in some of or all the species of Lobelia, as described by Mr. Farrer.) The pistil as it slowly increases in length pushes the pollen out of the conjoined anthers, by the aid of a ring of bristles; the two lobes of the stigma being at this time closed and incapable of fertilisation.  The extrusion of the pollen is also aided by insects, which rub against the little bristles that project from the anthers.  The pollen thus pushed out is carried by insects to the older flowers, in which the stigma of the now freely projecting pistil is open and ready to be fertilised.  I proved the importance of the gaily-coloured corolla, by cutting off the large flowers of Lobelia erinus; and these flowers were neglected by the hive-bees which were incessantly visiting the other flowers.

A capsule was obtained by crossing a flower of L. ramosa with pollen from another plant, and two other capsules from artificially self-fertilised flowers.  The contained seeds were sown on the opposite sides of four pots.  Some of the crossed seedlings which came up before the others had to be pulled up and thrown away.  Whilst the plants were very small there was not much difference in height between the two lots; but in Pot 3 the self-fertilised were for a time the tallest.  When in full flower the tallest plant on each side of each pot was measured, and the result is shown in Table 5/68.  In all four pots a crossed plant flowered before any one of its opponents.

Table 5/68.  Lobelia ramosa (First Generation).

Heights of plants measured in inches.

Column 1:  Number (Name) of Pot.

Column 2:  Tallest Crossed Plant in each Pot.

Column 3:  Tallest Self-fertilised Plant in each Pot.

Pot 1 :  22 4/8 :  17 4/8.

Pot 2 :  27 4/8 :  24.

Pot 3 :  16 4/8 :  15.

Pot 4 :  22 4/8 :  17.

Total :  89.0 :  73.5.

The four tallest crossed plants averaged 22.25, and the four tallest self-fertilised 18.37 inches in height; or as 100 to 82.  I was surprised to find that the anthers of a good many of these self-fertilised plants did not cohere and did not contain any pollen; and the anthers even of a very few of the crossed plants were in the same condition.  Some flowers on the crossed plants were again crossed, four capsules