The two forms are shown in Figure 7.12.
I did not at first doubt that this species existed under an hermaphrodite and
female form; but we shall presently see that some of the bushes which appear to
be hermaphrodites never produce fruit, and these are in fact males. The species,
therefore, is polygamous in the sense in which I use the term, and trioecious.
The flowers are frequented by many Diptera and some small Hymenoptera for the
sake of the nectar secreted by the disc, but I did not see a single bee at work;
nevertheless the other insects sufficed to fertilise effectually female bushes
growing at a distance of even 30 yards from any polleniferous bush.
The small anthers borne by the short stamens of the female flowers are well
formed and dehisce properly, but I could never find in them a single grain of
pollen. It is somewhat difficult to compare the length of the pistils in the two
forms, as they vary somewhat in this respect and continue to grow after the
anthers are mature. The pistils, therefore, in old flowers on a polleniferous
plant are often of considerably greater length than in young flowers on a female
plant. On this account the pistils from five flowers from so many hermaphrodite
or male bushes were compared with those from five female bushes, before the
anthers had dehisced and whilst the rudimentary ones were of a pink colour and
not at all shrivelled.
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