dust formed in the anthers, which is carried from flower to flower. In
the pines and oaks, this is done by the wind. But in other cases insects
visit a flower to get the honey, and in so doing get covered with
pollen, which they carry away and leave in the next 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