Weight of seeds produced by the same number of intercrossed and self-fertilised plants as 100 to 73.

It is also a remarkable fact that the Chelsea-crossed plants exceeded the two other lots in hardiness, as greatly as they did in height, luxuriance, and fertility.  In the early autumn most of the pots were bedded out in the open ground; and this always injures plants which have been long kept in a warm greenhouse.  All three lots consequently suffered greatly, but the Chelsea-crossed plants much less than the other two lots.  On the 3rd of October the Chelsea-crossed plants began to flower again, and continued to do so for some time; whilst not a single flower was produced by the plants of the other two lots, the stems of which were cut almost down to the ground and seemed half dead.  Early in December there was a sharp frost, and the stems of Chelsea-crossed were now cut down; but on the 23rd of December they began to shoot up again from the roots, whilst all the plants of the other two lots were quite dead.

Although several of the self-fertilised seeds, from which the plants in the right hand column in Table 3/20 were raised, germinated (and were of course rejected) before any of those of the other two lots, yet in only one of the ten pots did a self-fertilised plant flower before the Chelsea-crossed or the intercrossed plants growing in the same pots.  The plants of these two latter lots flowered at the same time, though the Chelsea-crossed grew so much taller and more vigorously than the intercrossed.

As already stated, the flowers of the plants originally raised from the Chelsea seeds were yellow; and it deserves notice that every one of the twenty-eight seedlings raised from the tall white variety fertilised, without being castrated, with pollen from the Chelsea plants, produced yellow flowers; and this shows how prepotent this colour, which is the natural one of the species, is over the white colour.

The effects on the offspring of intercrossing flowers on the same plant, instead of crossing distinct individuals.

In all the foregoing experiments the crossed plants were the product of a cross between distinct plants.  I now selected a very vigorous plant in Table 3/20, raised by fertilising a plant of the eighth self-fertilised generation with pollen from the Chelsea stock.  Several flowers on this plant were crossed with pollen from other flowers on the same plant, and several other flowers were fertilised with their own pollen.  The seed thus produced was allowed to germinate on bare sand; and the seedlings were planted in the usual manner on the opposite sides of six pots.  All the remaining seeds, whether or not in a state of germination, were sown thickly in Pot 7; the three tallest plants on each side of this latter pot being alone measured.  As I was in a hurry to learn the result, some of these seeds were sown late in the autumn, but the plants grew so irregularly during the winter, that one crossed plant was 28 1/2 inches, and two others only 4, or less than 4 inches in height, as may be seen in Table 3/21.  Under such circumstances, as I have observed in many other cases, the result is not in the least trustworthy; nevertheless I feel bound to give the measurements.