The
remainder of the plants were left uncovered and were incessantly visited
by bees, so that they were doubtless crossed by them. These exposed
plants yielded rather more and finer seed (but still very few) than did
the covered plants. The two lots of seeds thus obtained were sown on
opposite sides of two pots; the seedlings were carefully observed from
their first growth to maturity, but they did not differ at any period in
height or in vigour, the importance of which latter observation we shall
presently see. When fully grown, the tallest crossed plant in one pot
was a very little taller than the tallest self-fertilised plant on the
opposite side, and in the other pot exactly the reverse occurred. So
that the two lots were in fact equal; and a cross of this kind did no
more good than crossing two flowers on the same plant of Ipomoea or
Mimulus.
The plants were turned out of the two pots without being disturbed and
planted in the open ground, in order that they might grow more
vigorously. In the following summer all the self-fertilised and some of
the quasi-crossed plants were covered by a net. Many flowers on the
latter were crossed by me with pollen from a distinct plant, and others
were left to be crossed by the bees. These quasi-crossed plants produced
rather more seed than did the original ones in the great clump when left
to the action of the bees. Many flowers on the self-fertilised plants
were artificially self-fertilised, and others were allowed to fertilise
themselves spontaneously under the net, but they yielded altogether very
few seeds.
Pages:
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155