ext flower visited. Now
one of our commonest and most useful plants, the red clover, is so
constructed that it can only be fertilized by humble bees. If this bee
became extinct, the plant would die out; how can such a development be
advantageous to it?

But the contrivances by which this process of fertilization is secured
are so marvellous, that I confess I am completely staggered by the idea
that these contrivances have been caused by the self-growth and
adaptation of the plant without guidance. There is a plant called
_Salvia glutinosa_[1]--easily recognized by its sticky calyx and pale
yellow flowers. The anthers that bear the pollen are hidden far back in
the hood of the flower, so that the pollen can neither fall nor can the
wind carry it away; but the two anthers are supported on a sort of
spring, and directly a bee goes to the flower and pushes in his head to
get the honey, the spring is depressed and both anthers start forward,
of course depositing their pollen on the hairy back of the bee, which
carries it to the stigma of the next flower. This process can be tested
without waiting for a bee, by pushing a bit of stick into the flower,
when the curious action described will be observed. It is very easy to
say that this admirable mechanical contrivance is of great use to the
plant _in its complete_ form; but try and imagine what use an
intermediate form would have been! If development at once proceeded to
the complete form, surely this marks _design_; if not, no partial step
towards it would have been of any use, and therefore would not have been
inherited and perpetuated so as to prepare for further completion. But
many other plants have a structure so marvellous that this objection is
continually applicable. Let me only recall one other case, that of the
orchid, called _Coryanthes macrantha_. In this flower there are two
little horns, which secrete a pure water, or rather water mixed with
honey. The lower part of the flower consists of a long lip, the end of
which is bent into the form of a bucket hanging below the horns. This
bucket catches the nectar as it drops, and is furnished with a spout
over which the liquid trickles when it is too full. But the mouth of the
bucket is guarded by a curiously ridged cover with two openings, one on
each side. The most ingenious man, says Mr. Darwin, would never by
himself make out what this elaborate arrangement was intended for. It
was at last discovered. Large humble be