er opens one set of stamens
ripen and expose their pollen. Towards morning these wither away, the
flower shrivels up, ceases to emit scent, and looks as if it were faded.
So it remains all next day. Towards evening it reopens, the second set
of stamens have their turn, and the flower again becomes fragrant. By
morning, however, the second set of stamens have shrivelled, and the
flower is again asleep. Finally on the third evening it reopens for the
last time, the long spiral stigmas expand, and can hardly fail to be
fertilised with the pollen brought by Moths from other flowers.

THE HEATH

In the hanging flowers of Heaths the stamens form a ring, and each one
bears two horns. When the Bee inserts its proboscis into the flower to
reach the honey, it is sure to press against one of these horns, the
ring is dislocated, and the pollen falls on to the head of the insect.
In fact, any number of other interesting cases might be mentioned.

BEES AND FLIES

Bees are intelligent insects, and would soon cease to visit flowers
which did not supply them with food. Flies, however, are more stupid,
and are often deceived. Thus in our lovely little Parnassia, five of the
ten stamens have ceased to produce pollen, but are prolonged into
fingers, each terminating in a shining yellow knob, which looks exactly
like a drop of honey, and by which Flies are continually deceived.
Paris quadrifolia also takes them in with a deceptive promise of the
same kind. Some foreign plants have livid yellow and reddish flowers,
with a most offensive smell, and are constantly visited by Flies, which
apparently take them for pieces of decaying meat.

[Illustration: Fig. 14.--Arum.]

The flower of the common Lords and Ladies (Arum) of our hedges is a very
interesting case. The narrow neck bears a number of hairs pointing
downwards. The stamens are situated above the stigma, which comes to
maturity first. Small Flies enter the flower apparently for shelter, but
the hairs prevent them from returning, and they are kept captive until
the anthers have shed their pollen. Then, when the Flies have been well
dusted, the hairs shrivel up, leaving a clear road, and the prisoners
are permitted to escape. The tubular flowers of Aristolochia offer a
very similar case.

PAST HISTORY OF FLOWERS

If the views here advocated are correct, it follows that the original
flowers were small and green, as wind-fertilised flowers are even now.
But such flowers are i