We have just seen that
the mean of the mean heights of the crossed plants of the whole
fifty-four species in Table 7/A is to that of the self-fertilised plants
as 100 to 87; whereas the mean of the mean heights of the plants crossed
by a fresh stock is to that of the self-fertilised in Table 7/C as 100
to 74. So that the crossed plants beat the self-fertilised plants by
thirteen per cent in Table 7/A, and by twenty-six per cent, or double as
much, in Table 7/C, which includes the results of the cross by a fresh
stock.
TABLE 7/B.
A few words must be added on the weights of the crossed plants of the
same stock, in comparison with the self-fertilised. Eleven cases are
given in Table 7/B, relating to eight species. The number of plants
which were weighed is shown in the two left columns, and their relative
weights in the right column, that of the crossed plants being taken as
100. A few other cases have already been recorded in Table 7/C in
reference to plants crossed by a fresh stock. I regret that more trials
of this kind were not made, as the evidence of the superiority of the
crossed over the self-fertilised plants is thus shown in a more
conclusive manner than by their relative heights. But this plan was not
thought of until a rather late period, and there were difficulties
either way, as the seeds had to be collected when ripe, by which time
the plants had often begun to wither.
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