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Updated: May 26, 2025
This direct approach, so necessary in many orchids, is insured by various devices by the position of the lip upon which the insect must alight; by the narrowed entrance of the throat of the flower in front of the nectary; by a fissure in the centre of the lip, by which the tongue is conducted, etc.
The throat of the nectary, thus centrally divided, presents two small lateral openings, each of which, from the line of approach through the much-narrowed entrance of the flower, is thus brought directly beneath the waiting disc upon the same side. The structure is easily understood from the two diagrams Figs. 12 and 13, both of which are indexed.
At this time they are in the upright position shown at C, but in a few seconds bend determinedly downward and slightly towards each other to the position D. This change takes place as the moth is flitting from flower to flower. At E we see the moth with its tongue entering the nectary of a subsequent blossom.
This would insure its fertilization by the pollen on the insect's tongue; and even though the sipper failed to reach the nectar, the pollen would be withdrawn upon the tongue, to be carried to other flowers, which might thus be expected to inherit from the paternal side the tendency to the longer nectary.
The tendency towards the perpetuation of the short nectary is therefore stopped, while that of the longer nectary is insured. The singular hospitality of our milkweed blossom is nowhere matched among Flora's minions, and would seem occasionally in need of supervision.
Many of the group Habenaria or Platanthera, to which this flower belongs, are similarly planned. But mark the peculiarly logical association of the parts here exhibited. The nectary implies a welcome to a tongue two inches long, and will reward none other. This clearly shuts out the bees, butterflies, and smaller moths. What insect, then, is here implied?
What an immediate and expressive welcome! The nectary now drained of its sweets, the moth creeps or flutters to a second blossom, and its pollen-dusted body thus coming in contact with its stigma, cross-fertilization is accomplished.
This particular blossom would thus be both barren and sterile. None of its pollen would be carried to other stigmas, nor would it set a seed to perpetuate by inheritance its shorter nectary. Again, let us suppose the variation of an extra long nectary, and the writer recently saw a number of these orchids with nectaries thirteen inches in length.
Darwin's reply was magnificent in its proof of the sublime conviction of the truth of his belief: "The existence of an orchid with a slender nectary eleven inches in length, and with nectar secreted at its tip, is a conclusive demonstration of the existence of a moth with a tongue eleven inches in length, even though no such moth is known."
Adansonia the largest tree known, its dimensions Bulbous roots contain the embryon flower, seen by dissecting a tulip-root Flowers of Colchicum and Hamamelis appear in autumn, and ripen their seed in the spring following Sunflower turns to the sun by nutation, not by gyration Dispersion of seeds Drosera catches flies Of the nectary, its structure to preserve the honey from insects
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