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 bees were seen visiting the flower;
by way of getting at the honey, they set to work to gnaw off the ridges
of the lid above alluded to; in doing this they pushed one another into
the bucket, and had to crawl out by the spout. As they passed out by
this narrow aperture, they had to rub against the anthers and so carried
off the pollen. When a bee so charged gets into another bucket, or into
the same bucket a second time, and has to crawl out, he brushes against
the stigma, and leaves the pollen on it. I might well have adduced this
plant as another instance of the first objection, since it may well be
asked, How could such a development, resulting in a structure which
presents the greatest difficulty in the way of fertilization, be
beneficial to the plant? But here the point is that, even if any one
could assert the utility of such an elaborate and complicated
development, and suppose it self-caused by accident or effect of
environment, it certainly goes against the idea that all forms are due
to an _accumulation of small changes_. For these curious contrivances in
the case of _Salvia, Coryanthes_, and other plants, would in any case
have been no use to the plant till the whole machinery _was complete_.
Now, on the theory of slow changes gradually accumulating till the
complete result was attained, there must have been generation after