of the earlier ones on which I experimented, and as I had not then raised any self-fertilised plants for several successive generations under uniform conditions, I did not know or even suspect that such treatment would interfere with the advantages to be gained from a cross.  I was therefore much surprised at the crossed plants not growing more vigorously than the self-fertilised, and a large number of plants were raised, notwithstanding that the present species is an extremely troublesome one to experiment on.  The seeds, even those which have been long soaked in water, will not germinate well on bare sand; and those that were sown in pots (which plan I was forced to follow) germinated at very unequal intervals of time; so that it was difficult to get pairs of the same exact age, and many seedlings had to be pulled up and thrown away.  My experiments were continued during three successive generations; and in each generation the self-fertilised plants were again self-fertilised, their early progenitors in this country having probably been self-fertilised for many previous generations.  In each generation, also, the crossed plants were fertilised with pollen from another crossed plant.

Of the flowers which were crossed in the three generations, taken together, a rather larger proportion yielded capsules than did those which were self-fertilised.  The seeds were counted in forty-seven capsules from the crossed flowers, and they contained on an average 9.95 seeds; whereas forty-eight capsules from the self-fertilised flowers contained on an average 8.45 seeds; or as 100 to 85.  The seeds from the crossed flowers were not heavier, on the contrary a little lighter, than those from the self-fertilised flowers, as was thrice ascertained.  On one occasion I weighed 200 of the crossed and 106 of the self-fertilised seeds, and the relative weight of an equal number was as 100 for the crossed to 101.5 for the self-fertilised.  With other plants, when the seeds from the self-fertilised flowers were heavier than those from the crossed flowers, this appeared to be due generally to fewer having been produced by the self-fertilised flowers, and to their having been in consequence better nourished.  But in the present instance the seeds from the crossed capsules were separated into two lots,—­namely, those from the capsules containing over fourteen seeds, and those from the capsules containing under fourteen seeds, and the seeds from the more productive capsules were the heavier of the two; so that the above explanation here fails.

As pollen is deposited at a very early age on the pistil, generally in contact with the stigma, some flowers whilst still in bud were castrated for my first experiment, and were afterwards fertilised with pollen from a distinct plant.  Other flowers were fertilised with their own pollen.  From the seeds thus obtained, I succeeded in rearing only three pairs of plants of equal age.  The three crossed plants averaged 32.79 inches, and the three self-fertilised 32.08 inches in height; so that they were nearly equal, the crossed having a slight advantage.  As the same result followed in all three generations, it would be superfluous to give the heights of all the plants, and I will give only the averages.