Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/57

. I. either in the nectary or on the labellum of O. morio, fusca, militaris, maculata or latifolia. I have looked to all our common British species and could find no trace of nectar; I examined, for instance, eleven flowers of O. maculata, taken from different plants growing in different districts, and taken from the most favourable position on each spike, and could not find under the microscope the smallest bead of nectar. Sprengel calls these flowers "Scheinsaftblumen," or sham-nectar-producers;—he believes that these plants exist by an organized system of deception, for he well knew that the visits of insects were indispensable for their fertilisation. But when we reflect on the incalculable number of plants which have lived during a great length of time, all requiring that insects should carry the pollen-masses from flower to flower in each generation; and as we further know from the number of the pollen-masses attached to their proboscides, that the same insects visit a large number of flowers, we can hardly believe in so gigantic an imposture. He who believes in Sprengel's doctrine must rank the sense or instinctive knowledge of many kinds of insects, even bees, very low in the scale. To test the intellect of moths and butterflies I tried the following little experiment, which ought to have been tried on a larger scale. I removed a few already-opened flowers on a spike of O. pyramidalis, and then cut off about half the length of the nectaries of the six next non-expanded flowers. When all the flowers were nearly withered, I found that thirteen of the fifteen upper flowers with perfect nectaries had their pollinia removed, and two alone had their pollinia still in the anther-cells; of the six flowers with their nectaries cut off, three had their pollinia removed, and three were still in place; and this in-