Page - 204 - in The Origin of Species
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Text of the Page - 204 -
204 ORIGIN OF SPECIES
which stand above it; and when the bucket is half full, the
water overflows by a spout on one side. The basal part of
the labellum stands over the bucket, and is itself hollowed
out into a sort of chamber with two lateral entrances
; with-
in this chamber there are curious fleshy ridges. The most
ingenious man, if he had not witnessed what takes place,
could never have imagined what purpose all these parts serve.
But Dr. Criiger saw crowds of large humble-bees visiting the
gigantic flowers of this orchid, not in order to suck nectar,
but to gnaw off the ridges within the chamber above the
bucket
; in doing this they frequently pushed each other into
the bucket, and their wings being thus wetted they could not
fly away, but were compelled to crawl out through the pas-
sage formed by the spout or overflow. Dr. Criiger saw a
"continual procession" of bees thus crawling out of their
involuntary bath. The passage is narrow, and is roofed over
by the column, so that a bee, in forcing its way out, first rubs
its back against the viscid stigma and then against the viscid
glands of the pollen-masses. The pollen-masses are thus
glued to the back of the bee which first happens to crawl out
through the passage of a lately expanded flower, and are
thus carried away. Dr. Criiger sent me a flower in spirits of
wine, with a bee which he had killed before it had quite
crawled out with a pollen-mass still fastened to its back.
When the bee, thus provided, flies to another flower, or to
the same flower a second time, and is pushed by its comrades
into the bucket and then crawls out by the passage, the
pollen-mass necessarily comes first into contact with the
viscid stigma, and adheres to it, and the flower is fertilised.
Now at last we see the full use of every part of the flower,
of the water-secreting horns, of the bucket half full of water,
"ivhich prevents the bees from flying away, and forces them
to crawl out through the spout, and rub against the properly
placed viscid pollen-masses and the viscid stigma.
The construction of the flower in another closely allied
orchid, namely the Catasetum, is widely different, though
serving the same end; and is equally curious. Bees visit
these flowers, like those of the Coryanthes, in order to gnaw
the labellum; in doing this they inevitably touch a long,
tapering, sensitive projection, or, as I have called it, the
back to the
book The Origin of Species"
The Origin of Species
- Title
- The Origin of Species
- Author
- Charles Darwin
- Publisher
- P. F. Collier & Son
- Location
- New York
- Date
- 1909
- Language
- English
- License
- PD
- Size
- 10.5 x 16.4 cm
- Pages
- 568
- Keywords
- Evolutionstheorie, Evolution, Theory of Evolution, Naturwissenschaft, Natural Sciences
- Categories
- International
- Naturwissenschaften Biologie
Table of contents
- EDITOR'S INTRODUCTION 5
- AN HISTORICAL SKETCH of the Progress of Opinion on the Origin of Species 9
- INTRODUCTION 21
- Variation under Domestication 25
- Variation under Nature 58
- Struggle for Existence 76
- Natural Selection; or the Survival of the Fittest 93
- Laws of Variation 145
- Difficulties of the Theory 178
- Miscellaneous Objections to the Theory of Natural Selection 219
- Instinct 262
- Hybridism 298
- On the Imperfection of the Geological Record 333
- On the Geological Succession of Organic Beinss 364
- Geographical Distribution 395
- Geographical Distribution - continued 427
- Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs 450
- Recapitulation and Conclusion 499
- GLOSSARY 531
- INDEX 541