The difference in the amount of
fruit produced by the two sets of bushes is all the more striking, as from the
sketches above given it is obvious that the stigmas of the polleniferous flowers
can hardly fail to receive their own pollen; whilst the fertilisation of the
female flowers depends on pollen being brought to them by flies and the smaller
Hymenoptera, which are far from being such efficient carriers as bees.
I now determined to observe more carefully during successive seasons some bushes
growing in another place about a mile distant. As the female bushes were so
highly productive, I marked only two of them with the letters A and B, and five
polleniferous bushes with the letters C to G. I may premise that the year 1865
was highly favourable for the fruiting of all the bushes, especially for the
polleniferous ones, some of which were quite barren except under such favourable
conditions. The season of 1864 was unfavourable. In 1863 the female A produced
"some fruit;" in 1864 only 9; and in 1865, 97 fruit. The female B in 1863 was
"covered with fruit;" in 1864 it bore 28; and in 1865 "innumerable very fine
fruits." I may add, that three other female trees growing close by were
observed, but only during 1863, and they then bore abundantly. With respect to
the polleniferous bushes, the one marked C did not bear a single fruit during
the years 1863 and 1864, but during 1865 it produced no less than 92 fruit,
which, however, were very poor.
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