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Darwin, Charles, 1809-1882

"The Different Forms of Flowers on Plants of the Same Species"

The diameters of the pollen-grains are as follows:--
Table 4.b. Oxalis Valdiviana. Diameters of pollen-grains in divisions of the
micrometer.
Column 1: Source of Pollen-grains.
Column 2: Minimum diameter.
Column 3: Maximum diameter.
From the:
Longest stamens of short-styled form : 8 to 9.
Mid-length stamens of short-styled form : 7 to 8.
Longest stamens of mid-styled form : 8.
Shortest stamens of mid-styled form : 8.
Mid-length stamens of long-styled form : 7.
Shortest stamens of long-styled form : 6.
Therefore the extreme difference in diameter is as 8.5 to 6, or as 100 to 71.
The results of Hildebrand's experiments are given in Table 4.27, drawn up in
accordance with my usual plan.
Table 4.27. Oxalis Valdiviana (from Hildebrand).
Column 1: Nature of the Union.
Column 2: Number of Flowers fertilised.
Column 3: Number of Capsules produced.
Column 4: Number of Seeds per Capsule.
Long-styled by pollen of longest stamens of short-styled. Legitimate union :
28 : 28 : 11.9.
Long-styled by pollen of longest stamens of mid-styled. Legitimate union :
21 : 21 : 12.0.
Long-styled by pollen of own and own-form mid-length stamens. Illegitimate union
:
40 : 2 : 5.5.
Long-styled by pollen of own and own-form shortest stamens. Illegitimate union :
26 : 0 : 0.
Long-styled by pollen of shortest stamens of short-styled.


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