But this conclusion
cannot be absolutely trusted, owing to the measurements given in Table
3/21, though these latter, from the cause already assigned, are very
much less trustworthy than the present ones.]
SUMMARY OF OBSERVATIONS ON Mimulus luteus.
In the three first generations of crossed and self-fertilised plants,
the tallest plants alone on each side of the several pots were measured;
and the average height of the ten crossed to that of the ten
self-fertilised plants was as 100 to 64. The crossed were also much more
fertile than the self-fertilised, and so much more vigorous that they
exceeded them in height, even when sown on the opposite side of the same
pot after an interval of four days. The same superiority was likewise
shown in a remarkable manner when both kinds of seeds were sown on the
opposite sides of a pot with very poor earth full of the roots of
another plant. In one instance crossed and self-fertilised seedlings,
grown in rich soil and not put into competition with each other,
attained to an equal height. When we come to the fourth generation the
two tallest crossed plants taken together exceeded by only a little the
two tallest self-fertilised plants, and one of the latter beat its
crossed opponent,--a circumstance which had not occurred in the previous
generations. This victorious self-fertilised plant consisted of a new
white-flowered variety, which grew taller than the old yellowish
varieties.
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