The degree to which many of the most important organs in these degraded flowers
have been reduced or even wholly obliterated, is one of their most remarkable
peculiarities, reminding us of many parasitic animals. In some cases only a
single anther is left, and this contains but few pollen-grains of diminished
size; in other cases the stigma has disappeared, leaving a simple open passage
into the ovarium. It is also interesting to note the complete loss of trifling
points in the structure or functions of certain parts, which though of service
to the perfect flowers, are of none to the cleistogamic; for instance the
collecting hairs on the pistil of Specularia, the glands on the calyx of the
Malpighiaceae, the nectar-secreting appendages to the lower stamens of Viola,
the secretion of nectar by other parts, the emission of a sweet odour, and
apparently the elasticity of the valves in the buried capsules of Viola odorata.
We here see, as throughout nature, that as soon as any part or character becomes
superfluous it tends sooner or later to disappear.
Another peculiarity in these flowers is that the pollen-grains generally emit
their tubes whilst still enclosed within the anthers; but this is not so
remarkable a fact as was formerly thought, when the case of Asclepias was alone
known. (8/28. The case of Asclepias was described by R.
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